[VxTextBuilder] Add VxTextTheme to change DefaultTextStyle of the text at theme level.

[AyushBherwani1998]

Is your feature request related to a problem? Please describe.
By default, VxTextBuilder uses default text style, and there's no way to change the default texts style on theme level. Normally, we could have wrap MaterialApp with DefaultTextStyle but there's already an open issue that Text doesn't inherit DefaultTextStyle beyond Scaffold. It's been 2 years to the issue, and it's really inconvenient to change the DefaultTextStyle for every page.

Describe the solution you'd like
The idea is to bring VxTextTheme which can be wrapped around MaterialApp to change the default text style through out the application. VxTextBuilder will give to priority to VxTextTheme if any or it will fall back to default.

[M-A-D-A-R-A]

i would like to work on this issue can you guide me though it @AyushBherwani1998 plz!! Thanks

[AyushBherwani1998]

@M-A-D-A-R-A the main issue here is how to access the TextStyle from parent. For an instance, we can introduce a VxTheme to define TextStyle but the main issue is how to access that VxTheme without context. Currently to build a text, we use this syntax "String".text.make(). For that TextStyle to be default we might have to change the syntax to "String".text(context).make(). We can also introduce a new extension of vXTextTheme to get the default TextStyle i.e. "String".text.vXTextTheme(context).make()