* move experiments to new branch&reorganise kv_snapshot
* walk&modify tests
* added delete from snapshot tests
* fmt
* state snapshot debug
* snapshot validation passed. copy state snapshot
* debug
* snapshot cursor.Prev test
* Prev works correct. Added Current check
* add err check
* added walk forward and backward test
* before refactoring
* refactoring
* execution with snapshot debug
* fix
* remove useless test
* before dupcursor implimentation
* tests with prev and delete works
* execution based on state snapshot passed
* remove useless tests
* blocks to 1140000 passed
* clean verifier
* cleanup state generation
* clean verify && seeder
* remove debug code
* tests passed
* fix lint
* save state
* test passed
* fix lint
* add state hash
* fix lint
* fix `make grpc` on new checkouts
* update proto files
* add some stub
* prototype with fake events
* notifying about events
* pass events
* events are being sent
* transfer headers to filters
* create the “filters” struct
* implement new heads
* PoC of New Heads subscription
* fix keep alive
* fixups for the client
* add “type” to the event
* support header event type on client
* better stage refactor
* fixup for the eth backend
* fixups
* fix tests
* fix tests
* fix linters
* address comments
* remove unused log
* save state
* save state
* save state
* refactoring
* fix
* save state
* save state
* fmt
* fix lint
* restore torrents for external downloader
* fix lint
* download
* skip debug test
* debug
* remote debug
* small cli fixes
* skip debug test
* external snapshot predownloader
* get rid of remote downloader
* fix lint
* clean makefile
* fix lint
* fix lint
* cleanup
* fix ci
* fmt
* remove proto from interfaces
* Squashed 'interfaces/' content from commit acd02bb94
git-subtree-dir: interfaces
git-subtree-split: acd02bb94c5a421aa8f8d1fd76cd8aad668e9fcb