[ticket/12656] Use lang keys for CLI command descriptions

PHPBB3-12656
[ticket/12656] Use lang keys for all CLI strings

PHPBB3-12656
[ticket/12656] Use utf8 ’ instead of escaping '

PHPBB3-12656
[ticket/12656] Fix typo

PHPBB3-12656
[ticket/12656] Fix syntax in language file

PHPBB3-12656
[ticket/12656] Fix typo for "purged extension"

PHPBB3-12656
Merge pull request #2772 from dhruvgoel92/ticket/12656

[ticket/12656] Translate existing CLI commands

* dhruvgoel92/ticket/12656:
  [ticket/12656] Fix typo for "purged extension"
  [ticket/12656] Fix syntax in language file
  [ticket/12656] Fix typo
  [ticket/12656] Use utf8 ’ instead of escaping '
  [ticket/12656] Use lang keys for all CLI strings
  [ticket/12656] Use lang keys for CLI command descriptions