Locale support - extract

[sjoblomj]

Locales are not supported in mpqcli, see #113. This PR adds locale support to the extract subcommand.

This PR builds on top of #119, which in turns builds on top of #118, which in turn builds on top of #117.

Related PRs:

• Locale support - read #120 - Adding locale support to the read subcommand
• Locale support - remove #122 - Adding locale support to the remove subcommand

[thomaslaurenson]

Think I need a little guidance on how to proceed with these PRs. Guess you can see the history, but a brief summary:

• Merged Locale support - base PR #118
• Merged Locale support - read #120
• Got an error on PR Locale support - create and add #119 and tried to merge main into the branch
  This seems to have broken the flow of the PRs. I have fixed this one to pass tests, but have a suspicion that it would be better practice to reset back to before my commit. I am not very versed in this type of multiple PR that build on top of each other, and think some advice or tidying from you would be the best option here. I don't want to break the code base or the functionality of the new locale feature.

[sjoblomj]

Think I need a little guidance on how to proceed with these PRs. Guess you can see the history, but a brief summary:

* Merged [Locale support - base PR #118](https://github.com/TheGrayDot/mpqcli/pull/118)

* Merged [Locale support - read #120](https://github.com/TheGrayDot/mpqcli/pull/120)

* Got an error on PR [Locale support - create and add #119](https://github.com/TheGrayDot/mpqcli/pull/119) and tried to merge main into the branch
  This seems to have broken the flow of the PRs. I have fixed this one to pass tests, but have a suspicion that it would be better practice to reset back to before my commit. I am not very versed in this type of multiple PR that build on top of each other, and think some advice or tidying from you would be the best option here. I don't want to break the code base or the functionality of the new locale feature.

I cherry-picked and force-pushed, so both this PR and #122 should be good to merge now. I'll sort out #115 and #116 later - in the meantime, we still have some open questions to decide on for those :)