K, V Iterator for DbSnapshot

[citizen-stig]

Description

DbSnapshot struct suppose to swap DB in state_db and native_db, so they can work on top of snapshots.
This PR adds 2 methods to DbSnapshot struct:

• get_largest - returns the value of the largest key in the schema
• get_prev - returns the value of the key, that is equal or lower that the given

Secondary changes

• Move SchemaBatch into its own file
• Replace HashMap in for BTreeMap inside ScemaBatch, so keys are sorted inside single snapshot
• Add new method to QueryManager trait, that allows to iterate over all key value pairs in reverse order.

Linked Issues

• Related to Data Availability re-orgs handling tracking issue #1023

Testing

Unit and integration tests have been added.

Docs

Docs on public methods have been added.

[codecov]

Codecov Report

Merging #1177 (1a22011) into nightly (1307350) will increase coverage by 1.6%.
Report is 8 commits behind head on nightly.
The diff coverage is 97.3%.

Additional details and impacted files

Files	Coverage Δ
adapters/mock-da/src/types/mod.rs	80.6% <100.0%> (+7.5%)	⬆️
full-node/db/sov-db/src/schema/tables.rs	86.4% <ø> (ø)
full-node/db/sov-schema-db/src/iterator.rs	98.6% <100.0%> (+0.4%)	⬆️
full-node/db/sov-schema-db/src/lib.rs	91.5% <100.0%> (-1.2%)	⬇️
full-node/db/sov-schema-db/src/schema_batch.rs	100.0% <100.0%> (ø)
full-node/db/sov-schema-db/src/test.rs	100.0% <100.0%> (ø)
rollup-interface/src/state_machine/da.rs	84.7% <ø> (ø)
adapters/avail/src/spec/hash.rs	0.0% <0.0%> (ø)
...de/sov-prover-storage-manager/src/dummy_storage.rs	96.5% <96.5%> (ø)
...sov-prover-storage-manager/src/snapshot_manager.rs	99.1% <99.1%> (ø)
... and 2 more

... and 15 files with indirect coverage changes