chore: update master with latests fixes and features from develop

Changes:

• feature: allow editing witness description field when the account is a witness
• feature: blockchain explorer added to the side panel
• fix: do not display community labels outside of the community
• fix: remove temporary error message when loading a post
• fix: rewards breakdown (NaN)
• fix: SP changed to HP on account popup
• fix: signup button prevented from wrapping
• docs: update contributor list and contribution rules
• chore: make alternative endpoint configurable with ENV variable
• chore: CI/CD workflow