get rid of CONFIG dicts

[leotrs]

Motivation

CONFIG dicts in manim classes are hard to debug, cannot be documented, and are an all around Bad Thing.

Explanation for Changes

Basically, every key in a CONFIG dict has been converted to a __init__ argument.

Testing Status

Local pass.

Further Comments

This is WIP. @cobordism and I are going to keep working on this.

This is a second try of #648. In that PR, I tried removing some keys from Mobject and its derivatives, and left some others intact. This proved to be the wrong approach. I know understand that CONFIG should be removed from a class as well as from all its ancestors at the same time.

In #648, I made the mistake of removing some positional arguments and turning them into keyword-only arguments. I've tried my best to be more careful here.

I believe that this does not actually introduce breaking changes. But even if it does, we have to discuss what kind of breaking changes we are comfortable with introducing, because CONFIG dicts must go sooner rather than later.

[cobordism]

Status update:

All CONFIGs and all digest_config have been removed.
All variables previously in the CONFIG dict are now keyword arguments to __init__ and are then set as object attributes.
This makes for some very large __init__ signatures and there is plenty of scope to clean this up, but the point is, this cleanup is now possible. You no longer run the risk of breaking something far away by refactoring the internals of one class.

All tests pass, all docs build - some have been rewritten themselves, specifically we removed all CONFIGs from the docstrings too.

An error message was added to Container.__init__ and Animation.__init__ if a CONFIG is present warning people to use keyword arguments instead.

[kolibril13]

Can this pr be closed in favour of #783?

[leotrs]

I believe so. @cobordism I think we can close this, no?