chore: Use raw string encoding to prevent AI translation errors

[LisoUseInAIKyrios]

Crowdin AI pre-translation has issues when using \n characters in strings, and it regularly replaces them with new line breaks (which are stripped away in non-raw strings and thus never appear in the app).

Using raw strings for new lines fixes it, because even if the AI gets confused and uses the wrong new line encoding, with raw strings it still works because both regular line breaks and \n are valid and work as intended.

Raw strings are also easier to edit on Crowdin because multiline text is shown and edited as multiline (and not a single line with \n sprinkled throughout).

[LisoUseInAIKyrios]

Speaking of Crowdin, I manually hide all the flutter strings on Crowdin (can be unhidden if needed), because some users are still making occasional edits to the strings but they are wasting their time since Flutter is on the way out.