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.

Jellyfin.Api/obj/Jellyfin.Api.csproj.nuget.dgspec.json

@@ -47,6 +47,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -533,6 +534,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1030,6 +1032,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1512,6 +1515,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2142,6 +2146,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2635,6 +2640,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3140,6 +3146,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3761,6 +3768,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3974,6 +3982,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -4467,6 +4476,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "noWarn": [
             "NU5104"
           ],
@@ -4966,6 +4976,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -5440,6 +5451,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -5925,6 +5937,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],

Jellyfin.Api/obj/project.assets.json

@@ -2823,6 +2823,7 @@
         }
       },
       "warningProperties": {
+        "allWarningsAsErrors": true,
         "warnAsError": [
           "NU1605"
         ],

Jellyfin.Api/obj/project.nuget.cache

@@ -1,6 +1,6 @@
 {
   "version": 2,
-  "dgSpecHash": "fuMnEJ8wltc=",
+  "dgSpecHash": "+VYchT3v1Fw=",
   "success": true,
   "projectFilePath": "E:\\Projects\\pgsql-jellyfin\\Jellyfin.Api\\Jellyfin.Api.csproj",
   "expectedPackageFiles": [