docs: cut changelog for v1.7.0

docs: cut changelog for v1.7.0

change: Sidechain primitives crates cleanup (#772)

Release candidate 1 for 1.7.0

test: use validator-1 in staging tests

test: use validator-1 in staging tests

chore: temp fix until devnet-services db-sync is synced

chore: temp fix until devnet-services db-sync is synced

fix: extend default timeout to 5 minutes (#683)

Refs: ETCM-9741

Release candidate 2 for 1.5.1