RestApi Lightpush endpoint implemented
* Openapi definition for lightpush rest api
* Update waku/node/rest/lightpush/handlers.nim
* Fix install handler naming, added negative test cases and fixes for restapi lightpush
* Fix error handling in lightpush rest handler
* Fix main success case - relay message that comes with pushRequest
* Fix rest relay serdes test with RelayWakuMessage validation changes
* Checking response message tests
Filter v2 rest api support implemented
Filter rest api documentation updated with v1 and v2 interface support.
Separated legacy filter rest interface
Fix code and tests of v2 Filter rest api
Filter v2 message push test added
Applied autoshard to Filter V2
Redesigned FilterPushHandling, code style, catch up apps and tests with filter v2 interface changes
Rename of FilterV1SubscriptionsRequest to FilterLegacySubscribeRequest, fix broken chat2 app, fix tests
Changed Filter v2 push handler subscription to simple register
Separate node's filterUnsubscribe and filterUnsubscribeAll