Add validation tooltip on tag creation

[balanza]

Description

Add a validation tooltip on tag creation. When the user type an unsupported character, the tooltip appears to communicate the failure; the tooltip disappears when adding a valid character.

The feature is added to all editable tags in the application.

[nelsonkopliku]

@balanza thanks for this, it looks good. I noted a couple of things.

Besides that, I also noticed that the validation regex is not protecting against the following @_-=+,,...:::.
I know, you did not touch the regex. Up to you whether you want to make it stricter.

[balanza]

Besides that, I also noticed that the validation regex is not protecting against the following @_-=+,,...:::.
I know, you did not touch the regex. Up to you whether you want to make it stricter.

@nelsonkopliku to be honest I thought it was the intended behavior. It costs me 1min to fix, beside that I prefer to have a dedicate PR (and issue) so that we can share and discuss any possible problems (e.g. that would make tags non-retrocompatibles). It sounds?

[nelsonkopliku]

Great @balanza! I am fine with a possible follow up on the regex, if needed.