[iOS] - Remove Claude Instant Strings and Rename Llama 13B

[Brandon-T]

Summary

• Remove ClaudeInstant
• Rename Llama 13B to Llama 3 8B.

Resolves brave/brave-browser#37988
Resolves brave/brave-browser#38071

Submitter Checklist:

• I confirm that no security/privacy review is needed and no other type of reviews are needed, or that I have requested them
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[Uni-verse]

Verified on iPhone 12 running iOS 17.5.1 using version 1.69 (37)

New Install

• Ensured that Llama 13B strings are replaced with Llama 3 8B in menus and chat.
• Ensured that Claude Instant strings are removed from Language Models in Leo menu, everywhere in chat and in the advanced settings menu.
• Ensured that starting new chat will show the correct strings.
• Ensured that tapping on the (i) in chat shows the dialog box with the correct introduction for the model selected.
• Ensured Learn More in the dialog box launches the Brave support page.

Example	Example	Example	Example	Example

Existing Users

• Ensured that upgrading from previous version with Claude Instant set as default LLM will now default to Claude 3 Haiku for non-premium users.
• Ensured that upgrading from previous version with Claude Instant set as default LLM will now default to Claude 3 Sonnet for premium users.