- API:
	- Replace `emergencyModeStaringTime` by `emercengyModeStartingBlock`
- Synchronizer:
	- Track emergency mode starting block
- cli/node
	- Add working coordinator config
- coordinator:
	- Retry handler for synchronizer stats in case of error (instead of
	  waiting for the next block to try again)
	- On init, trigger an initial call to the handler for synced block
	  before waiting for the synchronizer, to force the coordinator to start
	  its logic even if there's no new block right after the node has been
	  started (very useful for running in testnet where the frequency of
	  blocks is variable)
	- Merge Msg for synced block and updated vars into one: `MsgSyncBlock`.

Related to 445f26ec9f

Swagger Review

* WIP: rebase

* Make nullable fields use pointers

Add TxID calculation & New{Layer}Tx Type

New{Layer}Tx methods that compute the `TxID` & `TxType` values from the
transaction values:
- NewL1Tx
- NewL2Tx
- NewPoolL2Tx

Add TxID Scanner & Valuer for database/sql

HistoryDB & L2DB & API packages tests will need to be addapted to the
TestTransaction generation once is done.

* WIP rebase

* Combine both SQL DBs

* API and DB refactor