Add RTL layout chat support

[idomamia]

Pull Request Checklist

• Target branch: Pull requests should target the dev branch.
• Description: Briefly describe the changes in this pull request.
• Changelog: Ensure a changelog entry following the format of Keep a Changelog is added at the bottom of the PR description.
• Documentation: Have you updated relevant documentation Open WebUI Docs, or other documentation sources?
• Dependencies: Are there any new dependencies? Have you updated the dependency versions in the documentation?
• Testing: Have you written and run sufficient tests for the changes?
• Code Review: Have you self-reviewed your code and addressed any coding standard issues?

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Description

Add support for RTL layout only for the chat. The user can now choose the preferred layout, LTR (left-to-right) or RTL (right-to-left), via the interface settings. The default is LTR.

Notice that code blocks will remain in LTR as it is considered the modern standard for programming languages.

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Changelog Entry

Added

• Option to switch the chat layout from LTR to RTL in the settings (LTR is the default).
• English translation.
• Chat direction was added to the settings store.

Changed

• RTL layout support in the Chat components (except Code blocks).

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Additional Information

• A gif of my implementation:
  

• Related to feat: RTL support #2134

[tjbck]

Not sure if these are supposed to look like this.

[idomamia]

Not sure if these are supposed to look like this.

Fixed that, now the arrow will always be in LTR mode:
LTR:

RTL:

[tjbck]

LGTM, Thanks!