Add cobra flag completion suggestions

[avirtopeanu-ionos]

Hi! There is currently no support for flag value completions.

To achieve this, We need to access the flagCompletionFunctions map in the cobra package and retrieve the flag completion functions for a given command. I have opened an issue (spf13/cobra#1942) and submitted a PR (spf13/cobra#1943) in the cobra repository to add getters for the flagCompletionFunctions map.

I would appreciate your feedback on this feature and any suggestions you may have. Please feel free to check the linked issue and PR in the cobra repository for more context.

Thank you!

[avirtopeanu-ionos]

Update: spf13/cobra#1943 has been merged! Cobra-prompt can now implement handle flag-value completions!