TelephonicInput: requires validation for number , '+' and braces only

[SySagar]

Description
Currently the telephonic input accepts anything i.e. strings, numbers, symbols like %,&,) etc. It should be made to accept only numbers with few paramters like + and ()

Steps to reproduce

1. Go to fuselage components

2. Type anything inside the text field

3. It should show it as invalid rather it doesn't shows anything

Insert an image/gif

[preeesha]

Thanks for reporting the issue @SySagar.

I am working on this.

[SySagar]

@dougfabris Should I start working on this?

[preeesha]

Hey @SySagar, I am working on this and will create a PR soon.

[SySagar]

sure. No problem