Add change case operation and keep enum case

[mrliptontea]

Hi,

Thanks for this plugin, I was looking for a replacement for Inc-Dec-Value for Sublime Text in VS Code.

To be completely happy I missed a feature that when I try "incrementing" a word it would change its casing like so: lowercase → Capitalized → UPPERCASE. This PR adds that.

The case change will be applied unless the number or enum operation was applied first. This also introduced a "problem" if a word is technically an enum but doesn't match case exactly, like True → TRUE rather than True → False, so I also included this feature, which resolves #3.

Both features can be switched off to restore old behaviour using keepEnumCase and changeCase options.

[nmsmith22389]

Thank you! I have been so busy I haven't had a lot of time for this! Missing Inc-Dec-Value from Sublime is also why I made this 😄 I'll work on getting it up on the marketplace.

[LeBenLeBen]

Oh yes, I would love to see that happen, also missing this feature coming from Sublime. Thanks @mrliptontea !

[mrliptontea]

I would love to see this merged and published on the vs code marketplace 😬 @nmsmith22389