regex tester

[BofengLi-123]

What type of request is this?

New feature for an existing tool

Clear and concise description of the feature you are proposing

regex tester is in common use, hope to add this feature.

Is their example of this tool in the wild?

https://regex101.com/

Additional context

No response

Validations

• Check the feature is not already implemented in the project.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• Check that the feature can be implemented in a client side only app (IT-Tools is client side only, no server).

[sharevb]

Hi @BofengLi-123 , implemented in #1030