chore(appium,types,schema): create @appium/schema

`@appium/schema` is a package which was extracted from `appium`.  It _only_ contains the schema.  The impetus here was to avoid cyclical dependencies, since `appium` depends on `@appium/types`, and `@appium/types` depends on the schema.  This package breaks the cycle.

The `scripts/generate-schema-json.js` (which converts the compiled JS schema file into JSON) has moved into this package, and the generated JSON file is now under version control.  This is because the `generate-schema-types.js` script (previously `generate-schema-declarations`) depends on it, and `@appium/types` depends on the generated types.  The generated types are _also_ under version control.  I do not expect the schema to change often, so I believe the tradeoff to be worth it.

## @appium/schema

`lib/appium-config-schema.js` is the "single source of truth" for the schema.

## appium

- Removed schema source
- Removed namespaces from internal types because they suck (see change to `types/index.d.ts`)
- Removed unused `continuation-local-storage`
- Add dep for `@appium/schema`
- Added a TS project dependency on `@appium/schema`

## @appium/types

- The "sources" have moved from `src` to `lib` for consistency.
- `lib/appium-config.ts` (the generated types) are now under version control.
- `lib/schema/` has been removed (it previously held the JSON schema artifact)
- `scripts/generate-schema-declarations.js` becomes `scripts/generate-schema-types.js`
- Updated scripts in `package.json`
- Added dep for `@appium/schema`
- Added a TS project dependency on `@appium/schema`

## Other

- Reorganize root `tsconfig.json`; add `schema` reference; remove unused `noEmit: true`
- Sort root `package.json`
- Remove schema JSON and schema declarations scripts, since those are now both handled in their respective packages
- Remove `lint-staged` config for schema file, since it didn't work right anyway (still need to do something about this, but probably doesn't need to be in a precommit hook)
- Remove stuff from `.gitignore`

scripts/generate-schema-json.js

@@ -1,125 +0,0 @@
-#!/usr/bin/env node
-
-/**
- * This script takes the JSON schema (which is actually JS) in `appium` and converts it to JSON proper,
- * then outputs the result in a couple places.  It also copies the JSON schema into `@appium/types`
- * to avoid cyclical dependencies in TS.
- */
-
-// @ts-check
-
-/* eslint-disable no-console */
-
-const _ncp = require('ncp');
-const path = require('path');
-const {writeFile} = require('fs').promises;
-const {info, success, error} = require('log-symbols');
-
-const ncp = require('util').promisify(_ncp);
-
-/**
- * `appium` package root.
- */
-const APPIUM_ROOT = path.join(__dirname, '..', 'packages', 'appium');
-
-/**
- * Root of Appium artifacts.
- */
-const APPIUM_BUILD_DIR = path.join(APPIUM_ROOT, 'build', 'lib');
-
-/**
- * `@appium/types` package root
- */
-const TYPES_ROOT = path.join(__dirname, '..', 'packages', 'types');
-
-/**
- * Basename of exported `.json` file.
- */
-const JSON_FILENAME = 'appium-config.schema.json';
-
-/**
- * Path to source schema `.js`.
- *
- * This is the _build artifact_.  Node can use ES modules, but it cannot use them unless one of two things is true:
- * - `type: module` in `package.json`
- * - file `.mjs` extension
- *
- * Neither of these things is true, so we have to use the build artifact.
- */
-const SRC = path.join(APPIUM_BUILD_DIR, 'schema', 'appium-config-schema.js');
-
-/**
- * Destination(s) for `.json` output.
- * the one in `types` is for its `generate-schema-declarations` script; the other one is for general consumer usage.
- * These paths should be in `.gitignore`
- */
-const JSON_DESTS = [
-  path.join(TYPES_ROOT, 'schema', JSON_FILENAME),
-  path.join(APPIUM_BUILD_DIR, JSON_FILENAME),
-];
-
-/**
- * In order to avoid a circular dependency, `@appium/types` needs this file, because it computes types from the constant sources.  It is not possible to do this with a `.json` file, unfortunately.
- * Note that this is the _source_, not the build artifact. TS understands ESM better than Babel output, unsurprisingly.
- * See https://github.com/microsoft/TypeScript/issues/32063 for details
- */
-const COPY_SRC = path.join(APPIUM_ROOT, 'lib', 'schema', 'appium-config-schema.js');
-
-/**
- * It goes here. These should be in `.gitignore`
- */
-const COPY_DESTS = [
-  path.join(TYPES_ROOT, 'src', 'appium-config-schema.js')
-];
-
-
-async function write () {
-  /** @type {typeof import('appium/lib/schema/appium-config-schema.js')} */
-  let schema;
-  try {
-    schema = require(SRC).default;
-  } catch (err) {
-    throw new Error(
-      `${error} Failed to read ${SRC}; did you execute \`npm run build\` first?`,
-    );
-  }
-
-  const json = JSON.stringify(schema, null, 2);
-
-  for await (const dest of JSON_DESTS) {
-    try {
-      await writeFile(dest, json);
-      console.log(`${info} Wrote JSON schema to ${dest}`);
-    } catch (err) {
-      throw new Error(
-        `${error} Failed to write JSON schema to ${dest}: ${err.message}`,
-      );
-    }
-  }
-
-  for await (const dest of COPY_DESTS) {
-    try {
-      await ncp(COPY_SRC, dest);
-      console.log(`${info} Copied ${SRC} to ${dest}`);
-    } catch (err) {
-      throw new Error(`${error} Failed to copy schema module to ${dest}: ${err.message}`);
-    }
-  }
-}
-
-async function main () {
-  try {
-    await write();
-  } catch (err) {
-    console.log(err);
-    process.exitCode = 1;
-    return;
-  }
-  console.log(`${success} Done.`);
-}
-
-if (require.main === module) {
-  main();
-}
-
-module.exports = {main, write};