Increase the visibility of InputText._selectAllTexts() public, or provide an public alternative

[mysticfall]

Is your feature request related to a problem? Please describe.
Currently, there's no way to select the content of an InputText control programmatically. There is _selectAllText(), but it's a protected method, so it's unsuitable for ordinary use cases.

Describe the solution you'd like
I want either the _selectAllText() method to be a public method or an alternative public API to be provided.

Discussion
You must provide a link to the forum post where the initial discussion happened:

https://forum.babylonjs.com/t/is-there-an-alternative-to-inputtext-selectalltext/54636

[deltakosh]

Do you want to do a PR?

[mysticfall]

Thanks for the quick fix!