Make Scala 3 DSL use context functions, to avoid polluting scope with _.everyItem, _everyMapKey, etc extensions

[MateuszKubuszok]

It would require creating:

• a new phantom type
• turning all path functions in Scala 3 DSL from S => T into PhantomType ?=> S => T
• making all path extension methods require this phantom type
• updating macros that parse the selectors

Since this is a breaking change it could happen on 2.0.0-development branch.

Actually, it could be implemented on master, it's in a macro and all such code has to be erased by the compiler anyway - it's impossible to write a code that would stop compiling after migrating to a new version.