Import path to meta

[e111077]

Removed --add-import-path and changed it to --remove-import-meta. It might be useful to look at the individual commits to filter out all the tests

before:
The flag, --add-import-meta, that defaulted to false, would add

class extends PolymerElement {
  static get importPath() { return import.meta.url; }
}

Polymer({
  importPath: import.meta.url
});

This was no longer supported in Polymer/polymer#5180

after:
The flag is now --remove-import-meta (false by default). So, by default we insert:

class extends PolymerElement {
  static get importMeta() { return import.meta; }
}

Polymer({
  importMeta: import.meta
});

By adding the --remove-import-meta flag, the user can opt out of this insertion (which is now on by default).

[aomarks]

I would lean towards keeping --add-import-path and just changing the default to true.

[e111077]

implemented changes!

[aomarks]

I would just say "True by default. Add a static importMeta property to converted Polymer elements." or something (less negatives)