feat: make errors copyable

[Vinayak9769]

This PR implements the feature requested in #155.

Summary:

Added a copy button allowing users to copy the diagnostic message as plain text.

Local test

Before:

After:

Happy to tweak this if you want any changes! :)

[kevinramharak]

This looks solid, the only question is if an icon from codeicon representing the copy icon would be better than using the text.

[Vinayak9769]

Yep, I was considering that as well. I’ve now updated the implementation to use the copy icon.

Here's a screenshot:

[yoavbls]

Looks good to me

[bennycode]

@yoavbls, @Vinayak9769 & @kevinramharak What’s the difference between the copy icon next to the website icons and the copy icon that already appears next to the error message?

Screenshot:

[kevinramharak]

@bennycode That is the original error message, shown by VS Code TypeScript language features.
As stated in #155 (comment), if you hide those original error messages, you will miss out on a copy button.

[bennycode]

Cool! Thanks for the info. @yoavbls can you make a new release of the extension?

[yoavbls]

Of course, I'm just waiting for this to be merged:
#152
Hopefully this weekend and then I'll publish a new one