Epic on possible improvements

[l0kix2]

Here is a meta-discussion with links to other discussion, so each can be commented separately.

From the user (yt administrator) perspective:

• Linear update flow + UpdateSelectors #359
• Make updateSelector more flexible #361
• Detect all diffs for components including sts fields #366

From the developer (ytop contributor) perspective:

• Refactor components and manager interaction #362
• Component's code impovements #363
• Increase amount of tested components #364
• Improve test infrastructure #365