Fix check_app_name.sh: resolve FIXMEs and TODOs from #2118

[Geet42]

Fixes #2118

• Replaced global-variable-dependent check() function with per-pass inline logic
• Added cross-check between title.txt and strings.xml app_name per language
• Fixed subtitle stripping to handle em dash (—) and en dash (–) variants used in some title.txt files
• Added warning for strings that hardcode 'Catima' instead of using @string/app_name
• Fixed comma bug in ALLOWLIST array ("peo," -> "peo")