feat(tools): process HBS files in nested directories

[ilhan007]

Now the the tools will process HBS files within nested directories and produce the output "lit" files into the "dist",
maintaining the file structures.

FIXES #2065

src/
----> myComponent
       ----> MyComponent.hbs (nested lvl 1)

                  ----> myComponentBadge
                           ----> MyComponentBadge.hbs (nested lvl 2)


dist/generated/templates/
 ----> myComponent
           ----> MyComponent.hbs (nested lvl 1)

                     ----> myComponentBadge
                              ----> MyComponentBadge.hbs (nested lvl 2)

[vladitasev]

I think it would be safer to follow the same structure in the src/ and dist/generated/templates/ directories, because if you have dir1/MyComponent.js and dir2/MyComponent.js they will overwrite each other.

Another thing that comes to mind is: if people create subdirectories like common/ and store .hbs files such as headers, footers or other reusable parts, they would expect to find them in the same output directory.

What do you think? I don't strongly object against merging it like this, if there are specific reasons.