merge trails function added (#627)

* merge trails function added

* fix conflict resolve issues

* avoid incorrect authorship when merging trail comments

* require edit access for all selected trails before merge

* fix likes checkbox binding in trail merge modal

* improve error handling

* require editable target and deletable sources for merge

* avoid duplicate trail fetch during merge

* prevent duplicate likes when merging trails

* check photo download responses during trail merge

* add merge completion toast notifications

* cleanup

* small fixes

* move merge code to backend, option to merge single trail selection with similar one, automatic merge for integrations add as option, maintenance page to find and merge similar trails added

* fix build error

* fix

* docu, beautifying, refactoring

---------

Co-authored-by: Flomp <Flomp@users.noreply.github.com>

web/src/lib/models/integration.ts

@@ -3,6 +3,10 @@ export interface BaseIntegration {
     active: boolean
 }
 
+export interface IntegrationMergeSettings {
+    enabled: boolean;
+}
+
 export interface StravaIntegration extends BaseIntegration {
     clientId: string | number;
     clientSecret?: string;
@@ -13,6 +17,7 @@ export interface StravaIntegration extends BaseIntegration {
     expiresAt?: number;
     after?: string
     privacy: "original" | "settings"
+    merge: IntegrationMergeSettings;
 }
 
 export interface KomootIntegration extends BaseIntegration {
@@ -21,6 +26,7 @@ export interface KomootIntegration extends BaseIntegration {
     completed: boolean,
     planned: boolean
     privacy: "original" | "settings"
+    merge: IntegrationMergeSettings;
 }
 
 export interface HammerheadIntegration extends BaseIntegration {
@@ -29,6 +35,7 @@ export interface HammerheadIntegration extends BaseIntegration {
     completed: boolean,
     planned: boolean,
     after?: string
+    merge: IntegrationMergeSettings;
 }
 
 
@@ -45,4 +52,4 @@ export class Integration {
         this.komoot = komoot;
         this.hammerhead = hammerhead;
     }
-}
+}