(fix) store rework

[dummdidumm]

Reworks $store handling in the code base. Previously, svelte2tsx would transform $store access to something like (__get(store), $store). This is now no longer the case. This means we need to add some extra code to some of the intellisense features:

• if someone renames a $store, store also needs to be renamed and vice versa
• if someone wants to find references of a $store, we also need to find store references and vice versa
• if someone wants to go to the definition of a $store, we need to reroute that to store
• if someone wants to go to the implementation of a $store, we need to reroute that to store
• diagnostics of wrong $store usages need to be handled

This means some more code overall, but I feel it's the better choice since we had so many edge cases with our transformation other time, and #1475 being an upstream bug we cannot solve ourselves but need to solve for the new transformation.

[jasonlyu123]

Maybe we also need to check the $store variable in the go-to-implementation. Probably only need to check for store for $store and don't need the other way around.

[dummdidumm]

Do you mean "right-click on $store -> Go to implementations -> get taken to store"?

[dummdidumm]

Added that, thanks for noticing. Does this look good to otherwise or is there something that needs changing (codestyle, missing cases)?