Fixes for overrite for js and css files in theme

[SilinMykola]

Description (*)
Hi all! I checked overwriting javascript and styles files and made some changes.

1. Overwriting a template from a module:
   
   
   
2. Overwriting a template from a heme to another theme:
   
   
   
3. Overwriting a js from module to a theme:
   
   
   
4. Overwriting a js file from a theme to another theme:
   
5. Overwriting a js file from lib/web folder:
   
   
   
6. Overwriting a lib js files from one theme to another works to.
7. Overwriting styles for less and css files:
   
   
   
8. From one theme to another:
   

Fixed Issues (if relevant)

1. Fixes Not possible to override the js/css files from the lib/web/* folder #603
2. Fixes Template Override dialog provides incompatible options #602

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with integration/functional tests (if applicable)
• All automated tests passed successfully (all builds are green)

[SilinMykola]

@magento run all tests

[bohdan-harniuk]

Hello, @SilinMykola!

Thank you for your work here! It is great!

Regards,