Use `~` as the webpack alias for CE and EE javascripts folders

Problem to solve

Use a clear, concise alias to eliminate line changes when a file exists in both CE and EE.

Further details

@mikegreiling has been leading the charge for a new webpack alias which will resolve to /app/assets/javascripts in CE and /ee/app/assets/javascripts/ in EE. ~ is our current alias for the CE javascripts folder so executing this particular proposal would likely mean changing a large amount of our existing import statements.

Proposal

Use ~ as the dynamically resolved alias as it is already a widely recognized unix shortcut signifying the home directory. In GitLab CE ~ would resolve to /app/assets/javascripts whereas in EE it would resolve to /ee/app/assets/javascripts/. Another issue would likely need to be created in CE for changing the existing ~ implementation over to something like ce. The end result would be as follows:

• ce always resolves to /app/assets/javascripts
• ee resolves to /ee/app/assets/javascripts/ in EE
• ~ resolves to /app/assets/javascripts in CE and to /ee/app/assets/javascripts/ in EE