Feature: search strings in swift files by pattern "*".localized

[MarkParker5]

• find all localizable strings in swift files
• check if strings exist in the base file
• add missed strings to the base file
• show all string literals without .localized in the terminal and offer to localize them
• add option --autofill-base [ fill | show | skip ]
• add option --show-non-localized [bool]