chore(TS): IText behavior mixins

[ShaMan123]

Motivation

Description

Continues #8420
This PR migrates IText mixins into classes that are chained to create the final IText class.
I have treated itext_behavior as the base class, holding more general methods, while itext_key_behavior and itext_click_behavior hold specific methods. itext_key_behavior is also in charge of the hidden textarea since it is part of the key behavior scope.
I moved some methods around to accommodate my approach but this is far from perfect.
I would rename the classes as well.
I have used abstract methods to make it easier to migrate the mixins. A follow up should do a heavier refactor, moving more methods and making the mixins more defined in scope.

Changes

Gist

Proto chain as follows:

1. itext_behavior extends Text
2. itext_key_behavior
3. itext_click_behavior
4. ITEXT

In Action

[ShaMan123]

Build stats are wrong
The bundle was 93.x
FIXED by 1d9c4ed

Build Stats

file / KB (diff) bundled reduced* minified gzipped
fabric.min.js 1078.104 (+63.882) 331.222 (+30.636) 93.176 (+7.604)
src/mixins/itext_behavior.mixin.ts 43.055 (+43.055) 44.184 (+44.184)
src/mixins/itext_click_behavior.mixin.ts 9.402 (+9.402) 9.602 (+9.602)
src/mixins/itext_key_behavior.mixin.ts 19.997 (+19.997) 19.050 (+19.050)
src/mixins/object_interactivity.mixin.ts 20.364 (+0.001) 18.729 (0.000)
src/mixins/observable.mixin.ts 4.599 (+0.001) 3.374 (0.000)
src/mixins/text_style.mixin.ts 9.339 (+9.339) 9.283 (+9.283)
src/shapes/itext.class.ts 19.490 (-0.741) 18.364 (-2.820)
src/shapes/text.class.ts 54.621 (-5.601) 50.654 (-12.394)
src/shapes/textbox.class.ts 14.160 (-1.123) 14.104 (-3.030)
*inaccurate, see link

[asturur]

Tried my best for conflicts, let's see.
Decription sucks.

[asturur]

28kb what? is that broken again?

[ShaMan123]

Updated description

[ShaMan123]

b94dff4 fixed the wrong stats

[ShaMan123]

2kb less 🥳 after minification!

[asturur]

So we know that text mixins are messy. I don't think right now renaming classes/mixins/files is a good idea.
Important is that we type what is typeable.
There is code that can probalby improved in the text interaction area, let's collect ideas in a doc with examples and let's move one. is on par or better than before and that is what it count since this is a tech migration

[ShaMan123]

Agreed

[asturur]

@ShaMan123 i ll start Static canvas today, and i look forward merging Image and observable types when we can.
I also know you probably want to look at group?

[ShaMan123]

Yep. Started group. Will try to fix the failing test in Image.
What about the animation pr?