Reduce JS library

[nulls]

We build save-common for JS, since we need plugin configurations on frontend. But ProcessBuilder and file system methods are not implemented for JS. Need to resolve these exception.

We can do it in two ways:

• Extract an utils methods from save-common which don't have implementation on JS. Cons: save-common uses these utils methods in core and need to refactor it
• Extract all configurations about plugins to a new module save-api which will have JS as a target. Cons: refactoring in save-cli and save-cloud