Add webjar locator

What does this mr do?

Change the way webjars are handled

before

Includes of any file from the webjar required specific version numbers resulting in too many changes when doing a minor version bump for security fixes.

after

html templates no longer change; only exception is popper.js; it does not behave nicely without version number it seems...

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made.
• Tests were created to test the feature.
• I have updated the documentation accordingly.
• I adhere to the style guide.