Implements:

• Pioneer upgrade: Required changes in core apps #1131
• Pioneer upgrade: joy-settings, joy-utils, joy-members #1132

Changes:

• Adjusted styles and functionality of the new polkadot-js/apps based on our old, modified apps (ie. added providers in Apps, added our types to api, added TopBar with account dropdown-select, adjusted the routes/tabs). I tried to limit the amout of those changes to the absolute minimum.
• Partially re-activated joy-utils. Moved all required functionality to new joy-utils directory, did some refactoring and put the files inside a new, more clean directory structure.
• Reactivated joy-members and joy-pages and did all the necessary adjustments.
• Disabled some linter rules that could cause too much chaos during the upgrade
• Fixed remaining linter issues

Draft:
Based on: #1101
Merged #1153 for new node compatibility

Commits of intrest:

• Almost all of the work: ea711c9
• Linter rules adjustment + autofix: 15e1c69
• Manual linter fixes: 83d22c4
• Icons/title changes: 8a8f85a

Testing:

1. Run dev chain based on fb9845b (currently should already be part of https://github.com/Joystream/joystream/tree/substrate_version_upgrade)
2. yarn workspace pioneer start or use deploy preview at https://deploy-preview-1156--joystream-pioneer.netlify.app/
3. Change endpoint to local node (ie. by clicking the Joystream logo in the top-left corner)