Add UI

[VladislavSokov]

• [x] add icons to the buttons
• [x] move logic from controller to a service
• [x] refactor with "each db connection"
• [x] intro new env var for "disabled"

[VladislavSokov]

[ka8725]

Manual testing results:

1. down migration cannot be rolled back, so hide the button?

   

2. If no phantom migrations the table looks clunky

   

   Show some text saying no phantom migrations instead of the empty table? Or fix the table look so it's clear what's going on.

3. WDYT if we don't show down phantom migrations in the table at all? Reason - there is no point in running it up and also since it's down the user cannot do with it anything. This kind of migration is useless for the current branch too. So if it's hidden the user won't notice. It's not a relevant thing that can be destroyed. I tend to think we can remove it entirely on down. Please tell what do you think, thanks!

[VladislavSokov]

3. WDYT if we don't show down phantom migrations in the table at all? Reason - there is no point in running it up and also since it's down the user cannot do with it anything. This kind of migration is useless for the current branch too. So if it's hidden the user won't notice. It's not a relevant thing that can be destroyed. I tend to think we can remove it entirely on down. Please tell what do you think, thanks!

I think this is a great idea