Add horizontal alignment support to RichTextLabel

[Kofeecheks]

Robust.Client/UserInterface/Controls/RichTextLabel.cs
Added Align property to RichTextLabel with Left as the default behavior.
Updated the draw path to pass the requested alignment into RichTextEntry.Draw(...).

Robust.Client/UserInterface/RichTextEntry.cs
Extended Draw(...) to support horizontal alignment at the rich-text layout level.
Added per-line width calculation so wrapped text is aligned line by line instead of shifting the whole text block.
Updated baseline positioning on line breaks to apply Center / Right offsets correctly.
Refactored ProcessNode(...) to take tagsAllowed explicitly so the new draw and measurement paths can reuse the same parsing logic.

Result
RichTextLabel now supports correct horizontal alignment for wrapped rich text, including multi-line content and inline controls, while preserving existing left-aligned behavior by default.

[moonheart08]

This needs screenshots of:

• The game functioning as intended in various UI states (i.e. lobby, control zoos, etc)
• The feature functioning as intended on various sample texts (incl. font size and color changes, wrapping, etc.)

[Kofeecheks]

This needs screenshots of:

• The game functioning as intended in various UI states (i.e. lobby, control zoos, etc)
• The feature functioning as intended on various sample texts (incl. font size and color changes, wrapping, etc.)

This pull request is part of the effort to add a table and content rendering system to the Media Wiki for the Russian server.

dead-space-server/space-station-14-soyuz#157

https://youtu.be/sLDwr7JNSzc

[Kofeecheks]

@moonheart08 you can merge?

[moonheart08]

I can't easily review this video and need to spend time testing this myself when I have time unless screenshots and ideally a UITestControl page are provided for demonstrating this works.