Add JSON format to import blocks and set it as default (#5816)

* Add BlockStream Enum and utility fn

* WIP: Modify import closure to work with BlockStream

* Fix trait bounds

* Working prototype

* Revamp block importing

* Add export_import_flow tests

* Add comments and clean code

* Add more comments in the import fn

* Add link code to import function

* Add condition when returning Ready(Ok(()) to make sure we've imported every block

* Add check for imported blocks in JSON case

* Use rest pattern

* Fix compilation error for undeclared variable

* Add polling and waker before pending

* Print read_block_count instead of count

* Simplify binary cli option with structopt

* Update test to reflect changes in CLI api

* Change Stream to take SignedBlock<B> instead of B

* Add comments to BlockStream

* Move out logic to smaller functions for clearer code

* Remove result over import_blocks return type

* Check for error in command output rather than simply checking command exit status

* Revamp export/import/revert testing

* Fix minor typos and formatting errors

Co-authored-by: Bastian Köcher <[email protected]>

* Remove unnecessary if condition in terminating condition

Co-authored-by: Bastian Köcher <[email protected]>

* Explicit error instead of returning it as a string

Co-authored-by: Bastian Köcher <[email protected]>

* Pass BlockStream to log_importing_status_updates and simplify matching arms for block stream

* Use .contains() instead of regex match

* Line break in match block; return future::ready instead of poll_fn

* Update Cargo.lock

* Add check so that queue doesn't grow too big

* Use Iterator instead of Stream

* Remove allow dead_code

* Remove outdated comments

Co-authored-by: Bastian Köcher <[email protected]>

* Return Errors instead of logging them

* Simplify match arms

Co-authored-by: Bastian Köcher <[email protected]>

* Remove check before terminating block import

* Apply suggestions from code review

* Check that queue is not full BEFORE calling

* Revert "Remove check before terminating block import"

This reverts commit 377823c0

.

* Improve unit tests to make sure we actually import blocks

* Remove Unpin implementation for BlockIter

* Add prototype of enum for ImportStates

* Add working prototype for StateMachine

* Add comments for clearer code

* Add sleep before calling Waker when waiting for import queue

* Add Speedometer

* add dbg!(&log) for test debugging

* Fix lines with more than 100 cols

* Fix regex capture for test

* Update regexes to take to capture the whole number

* Rename Cmd to Command

Co-authored-by: Gavin Wood <[email protected]>

* Actually rename Cmd to Command

* Apply suggestions from code review

Co-authored-by: Gavin Wood <[email protected]>

* Fix compilation errors for tests

* Fix compilation errors from code review suggestion

* Update bin/node/cli/tests/export_import_flow.rs

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Gavin Wood <[email protected]>
Co-authored-by: Benjamin Kampmann <[email protected]>