refactor: drop bootstrap

[davidyuk]

closes #740

@Liubov-crypto would be nice to ensure that it doesn't add any significant visual bugs in both mobile and desktop

[github-actions[bot]]

Deployed to feature-drop-bootstrap.aggregator.z52da5wt.xyz, bundle report

[Liubov-crypto]

Tested in mobile and desktop browsers, in general LGTM: Trending - pass Search - pass Change profile/back pics - pass Change profile info - pass Cookies - pass Send Tip on the Feed - pass Retip on the feed - pass
Post without tipping - pass
Comment - pass Tip comment on the feed - pass Pin/Unpin - pass Claim - pass Report post - pass Voting - pass Vote - pass Revoke Vote - pass Delegate voting power - pass Create a new poll - pass Search - pass Meet - pass Updates - pass Faq- pass

also remains #1112 Not synced names in Meet UI and SH wallet.

I haven't been using the wallet for a while, got this error. But maybe this is the wallet side (#1180 in wallet issues):

It is possible to move the wallet to the left in the mobile browser:

[davidyuk]

It is possible to move the wallet to the left in the mobile browser

This issue persists in develop branch, so fixing it separately in #1127

All other issues seems to be resolved