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.

MediaBrowser.Providers/obj/MediaBrowser.Providers.csproj.nuget.dgspec.json

@@ -47,6 +47,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -524,6 +525,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1006,6 +1008,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -1636,6 +1639,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2126,6 +2130,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -2757,6 +2762,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3272,6 +3278,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3485,6 +3492,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],
@@ -3978,6 +3986,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "noWarn": [
             "NU5104"
           ],
@@ -4465,6 +4474,7 @@
           }
         },
         "warningProperties": {
+          "allWarningsAsErrors": true,
           "warnAsError": [
             "NU1605"
           ],

MediaBrowser.Providers/obj/project.assets.json

@@ -2262,6 +2262,7 @@
         }
       },
       "warningProperties": {
+        "allWarningsAsErrors": true,
         "warnAsError": [
           "NU1605"
         ],

MediaBrowser.Providers/obj/project.nuget.cache

@@ -1,6 +1,6 @@
 {
   "version": 2,
-  "dgSpecHash": "8nGSBHrHFM8=",
+  "dgSpecHash": "piLgjB8GOiQ=",
   "success": true,
   "projectFilePath": "E:\\Projects\\pgsql-jellyfin\\MediaBrowser.Providers\\MediaBrowser.Providers.csproj",
   "expectedPackageFiles": [