#2660 Can't attach copied or cutted Functional Group to atoms of structure

[kaluginserg]

Resolves #2660

What was done:

• Tool Paste
  • removed all logic related to drag functionality (it didn't work, so without proper tests and naming it's just trash)
  • removed flag isSingleContractedGroup as it is not working as expected, finally in the current implementation it works only when we past group on group, but if we try to past Atom on group or structure on structure, or group on atom - it's not working. So the decision is to have it as is, and later fix all issues with Past tool at once with the new implmementation.
• add the helper function filterSlatAndSolventFromMerge() in the tools folder. It's the short-term solution as in the better way it must be inside the ketcher-core closest.merge (the same as findCloseMerge), and removed from the tools level.
• small refactoring for related files (adding typescript types and interfaces)

How it works now (On the video: begining from Template, then using select tool, and after that using Paste tool):

Screen.Recording.2023-06-01.at.14.03.31.mov

It is still a difference in the behavior of the tools:

• Template Tool - the group is merged as collapsed
• Select tool - the group is merged as expanded
• Paste tool - the group is merged as expanded