[Feature] generate service in xplat architecture set up

[iameduardod]

Please add a "nx generate service --platforms..." option to generate a service in an xplat architecture pattern similar to the generate component CLI command.

@NathanWalker

[NathanWalker]

@iameduardod for all angular specific features you can use those schematics which come with xplat:

nx g @nstudio/angular:service auth --platforms=etc...