Previously the custom theme was vendored in via a `git` submodule...
Now this theme is available via a python package, so install it using `extras_require` instead.
This also unlocks letting other tooling such as ReadTheDocs install the custom theme without having to do custom git incantations.
I also removed the `index_logo` config as Sphinx warns that it's not a supported option by the theme. I grep'd the theme package, and it makes no mention of this option, besides we were leaving it blank already, so there's no point in having it.
Require Flask >= `2.2.0`.
I'm comfortable going up to requiring `3.x`, but when I grep'd for
places we use older Flask constructs, this was all I found.
So for now no need to jump further.
Flask `2.2.0` requires Python >= `3.7`, so also dropped older pythons.
The `packaging` lib is not listed in the `install_requires` list.
https://github.com/greyli/flask-extension-status/actions/runs/7129071225/job/19412328108
```
Run python -c "from flask import Flask; app = Flask(__name__); from flask_debugtoolbar import DebugToolbarExtension; DebugToolbarExtension(app)"
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/opt/hostedtoolcache/Python/3.12.0/x64/lib/python3.12/site-packages/flask_debugtoolbar/__init__.py", line 6, in <module>
from packaging import version as version_builder
ModuleNotFoundError: No module named 'packaging'
Error: Process completed with exit code 1.
```
Update to the newer PyPI / python packaging metadata file structure.
A lot of this was cribbed from how [`Flask`](https://github.com/pallets/flask) itself
exposes its metadata.
Fixing #31 where the query signing would break when the SECRET_KEY
contained non-ascii values. In the process switch to itsdangerous
instead of rolling our own signatures.
simplejson is only needed for the SQLAlchemy panel on Python < 2.6
Also, provides a nice error message in the SQLAlchemy panel about
missing dependencies.
