Improving developer experience with runtime warnings (#943)

* Perform thread check only when store is created on main thread.

* clean up

* Update Sources/ComposableArchitecture/Store.swift

* clean up

* Update Sources/ComposableArchitecture/Store.swift

* clean up

* execute setSpecific only once.

* logic fix

* added a test

* typo

* wip

* wip

* wip

* clean up

* language

* wip

* note

* wip

* wip

* wip

* wip

* wip

* fix closing quote

* wip

* fix merge

* Deprecations

* Fix docs

* wip

Co-authored-by: Brandon Williams <[email protected]>

Author: mluisbrown