refactor!: update to Quill v2, drop outdated Firefox patch

[web-padawan]

Description

Fixes #1680

WIP, all tests passed locally but this still needs some manual testing especially for htmlValue logic.

• Upgraded Quill to v2, branch in the fork: https://github.com/vaadin/quill/tree/proto/vaadin-quill-v2
• Replaced shadow selection polyfill with getComposedRanges() API available since Safari 17+
  • Based on the prototype from Quill misbehaves inside of Shadow DOM slab/quill#4250 (comment)
• Removed Firefox focus patch since the disappearing caret bug is fixed since Firefox 117
• Updated the htmlValue logic to use getSemanticHTML() API instead of innerHTML
  • This has some known issues e.g. I had to add a hack for restoring spellcheck="false" on <pre> tag
  • It also strips <code> tags e.g. when using dangerouslySetHtmlValue('<pre><code>123</code></pre>');
  • Several issues with getSemanticHTML not preserving html represented in editor slab/quill#4289
• Updated some tests where htmlValue contains   instead of regular whitespace
  • This was implemented in Handle consecutive spaces when copying and pasting slab/quill#4502
  • Affected a lot of users, see [2.0.3] getSemanticHTML is broken slab/quill#4509
  • UPD: applied a workaround to the Quill fork - see the comment below.
• Added styles for lists from Quill core (still missing indentation styles, could consider adding them later)
  • Quill uses li[data-list='bullet'] > .ql-ui::before with content: '\\2022'; for bullets - replaced those with native list-style-type for now (didn't manage to get custom bullets use correct vertical alignment).

Type of change

• Breaking change

[TatuLund]

Updated some tests where htmlValue contains   instead of regular whitespace (is this a bug?)

@web-padawan Not a bug, but by design how some Quill internal tags were removed to clean the html value: #6434 So I think change is valid as Quill has now method to get html value instead of our own hack.

[web-padawan]

Not a bug, but by design how some Quill internal tags were removed to clean the html value: #6434

I'm talking about a different logic added in #6651 and #6652 as a fix for vaadin/flow-components#5533.
So the following test now fails as getSemanticHTML() returns ' ' for preserved whitespaces.

web-components/packages/rich-text-editor/test/basic.test.js

Lines 318 to 323 in 76a7f05

	it('should not lose extra space characters from the resulting htmlValue', () => {
	const htmlWithExtraSpaces = '<p>Extra spaces</p>';
	rte.dangerouslySetHtmlValue(htmlWithExtraSpaces);
	flushValueDebouncer();
	expect(rte.htmlValue).to.equal(htmlWithExtraSpaces);
	});

UPD: this was introduced in slab/quill#4502 which landed in v2.0.3 patch release and a number of users were upset and had to pin to v2.0.2 - see discussion at slab/quill#4502 (comment) and this issue: slab/quill#4509

[web-padawan]

Updated the Quill fork to apply the workaround from slab/quill#4509 (comment), see vaadin/quill@76a4568.
This replaces all but one consecutive space character with  , which should be less intrusive.

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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