[feature] Implement markers API (#1989)

* Implement markers API

Fixes #1856

* Correct import grouping in markers files

* Regenerate Swagger for markers API

* Shorten names for readability

* Cache markers for 6 hours

* Update DB ref

* Update envparsing.sh

internal/db/marker.go

@@ -0,0 +1,32 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package db
+
+import (
+	"context"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+type Marker interface {
+	// GetMarker gets one marker with the given timeline name.
+	GetMarker(ctx context.Context, accountID string, name gtsmodel.MarkerName) (*gtsmodel.Marker, error)
+
+	// UpdateMarker updates the given marker.
+	UpdateMarker(ctx context.Context, marker *gtsmodel.Marker) error
+}