fix: undo scan for current sequence in get by id (#1956)

* index on events for changes

* check for current sequence before filter events

* fix(migration): enable hash shared indexes feature

* fix(database): drop changes idx as it slows unwanted queries

* fix: remove check for current sequence after objects loaded as not all events are processed

migrations/cockroach/V1.51__drop_changes_idx.sql

@@ -0,0 +1,3 @@
+use eventstore;
+
+drop index events@changes_idx;