[Run-UnitConverter] Use capital letters in DegreePrefixer

[PesBandi]

Summary of the Pull Request

f and c would previously get converted to °f and °c, now they get converted to °F and °C.
Also removes the FeetToFt() function, as it's not needed anymore

PR Checklist

• Closes: [Run-UnitConverter] Uses lowercase letters in DegreePrefixer #34842
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Dev docs: No need
• New binaries: None
• Documentation updated: No need

Detailed Description of the Pull Request / Additional comments

Before:

After:

Validation Steps Performed

Manually trying it in PTRun.