Remove resource bundle

[OlenaPostindustria]

#795

• remove resource bundle;
• use a static markup string in the code for companion.html;
• use base64 encoded data instead of assets;
• replace local mraid.js and omsdk.js with the scripts hosted on jsdeliver.

[YuriyVelichkoPI]

@OlenaPostindustria , please update the PR and study the opportunity to host mraid.js and omsdk.js on jsdelivr. Details in comments for the issue.

[YuriyVelichkoPI]

@OlenaPostindustria, please, add the description of managing the remote .js libraries so it can be reproduced on Android.

[OlenaPostindustria]

To host .js files on jsdelivr.com all we need to do is to paste Github link to file here and convert it to jsdelievr link. Then we can make GET request on that link to download scripts in SDK.

So, the algorithm for managing remote js libraries is as follows:

1. check if the scripts were already downloaded during SDK initialization: if not => download them;
2. if the scripts were successfully downloaded - save them in a cache directory named PBMJSLibraries;
3. if the SDK demands scripts:
   • search for cached library => fetch;
   • if there is no cached library => try to download it.

@ValentinPostindustria for visibility

[YuriyVelichkoPI]

LGTM