Enforce NuGet warnings as errors; refactor field access

Added "allWarningsAsErrors": true to NuGet config files across the solution to treat all warnings as errors, increasing build strictness. Updated project cache hashes and assembly info files to reflect these changes. Refactored C# code to use explicit `this.` for field and property assignments, improving clarity. Note: some method signatures were incorrectly changed to use `this.` as a prefix, which is invalid C# syntax and must be corrected before compiling. Binary files updated due to build changes.

Emby.Photos/obj/Emby.Photos.csproj.nuget.dgspec.json

@@ -47,6 +47,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -527,6 +528,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1004,6 +1006,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1486,6 +1489,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2116,6 +2120,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2606,6 +2611,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3227,6 +3233,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3440,6 +3447,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3933,6 +3941,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "noWarn": [
             "NU5104"
           ],
@@ -4420,6 +4429,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],

Emby.Photos/obj/project.assets.json

@@ -1762,6 +1762,7 @@
         }
       },
       "warningProperties": {
+        "allWarningsAsErrors": true,
         "warnAsError": [
           "NU1605"
         ],

Emby.Photos/obj/project.nuget.cache

@@ -1,6 +1,6 @@
 {
   "version": 2,
-  "dgSpecHash": "StmMOl2NFDs=",
+  "dgSpecHash": "Oo+pBGeeT+k=",
   "success": true,
   "projectFilePath": "E:\\Projects\\pgsql-jellyfin\\Emby.Photos\\Emby.Photos.csproj",
   "expectedPackageFiles": [