[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/client4.go

@@ -7931,3 +7931,16 @@ func (c *Client4) GetUsersWithInvalidEmails(page, perPage int) ([]*User, *Respon
 	}
 	return list, BuildResponse(r), nil
 }
+
+func (c *Client4) GetAppliedSchemaMigrations() ([]AppliedMigration, *Response, error) {
+	r, err := c.DoAPIGet(c.systemRoute()+"/schema/version", "")
+	if err != nil {
+		return nil, BuildResponse(r), err
+	}
+	defer closeBody(r)
+	var list []AppliedMigration
+	if jsonErr := json.NewDecoder(r.Body).Decode(&list); jsonErr != nil {
+		return nil, nil, NewAppError("GetUsers", "api.unmarshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+	}
+	return list, BuildResponse(r), nil
+}

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"`
+}