[MM-41576] Revamp database schema version (#19586)

* revamp db version and add applied migrations endpoint

* replace old schema version with new

* add db version subcommand

* add to local api

* reflect review comments

* log errors

* remove setting the version from model.CurrentVersion

* fix a test

model/system.go

@@ -173,3 +173,8 @@ type WarnMetricStatus struct {
 type SendWarnMetricAck struct {
 	ForceAck bool `json:"forceAck"`
 }
+
+type AppliedMigration struct {
+	Version int    `json:"version"`
+	Name    string `json:"name"`
+}