cmake: Add services preset with OAuth configurations

Allows the use of OAuth credentials set up via environment variables
(as used on CI) without the need for extra plumbing via build scripts.

Also sets GPU_PRIORITY_VAL via preset on Windows.

CMakePresets.json

@@ -6,10 +6,25 @@
     "patch": 0
   },
   "configurePresets": [
+    {
+      "name": "environmentVars",
+      "hidden": true,
+      "cacheVariables": {
+        "TWITCH_CLIENTID": {"type": "STRING", "value": "$penv{TWITCH_CLIENTID}"},
+        "TWITCH_HASH": {"type": "STRING", "value": "$penv{TWITCH_HASH}"},
+        "RESTREAM_CLIENTID": {"type": "STRING", "value": "$penv{RESTREAM_CLIENTID}"},
+        "RESTREAM_HASH": {"type": "STRING", "value": "$penv{RESTREAM_HASH}"},
+        "YOUTUBE_CLIENTID": {"type": "STRING", "value": "$penv{YOUTUBE_CLIENTID}"},
+        "YOUTUBE_CLIENTID_HASH": {"type": "STRING", "value": "$penv{YOUTUBE_CLIENTID_HASH}"},
+        "YOUTUBE_SECRET": {"type": "STRING", "value": "$penv{YOUTUBE_SECRET}"},
+        "YOUTUBE_SECRET_HASH": {"type": "STRING", "value": "$penv{YOUTUBE_SECRET_HASH}"}
+      }
+    },
     {
       "name": "macos",
       "displayName": "macOS",
       "description": "Default macOS build (single architecture only)",
+      "inherits": ["environmentVars"],
       "condition": {
         "type": "equals",
         "lhs": "${hostSystemName}",
@@ -44,6 +59,7 @@
       "name": "linux-aarch64",
       "displayName": "Linux aarch64",
       "description": "obs-studio for Linux (aarch64)",
+      "inherits": ["environmentVars"],
       "condition": {
         "type": "equals",
         "lhs": "${hostSystemName}",
@@ -80,6 +96,7 @@
       "name": "linux-x86_64",
       "displayName": "Linux x86_64",
       "description": "obs-studio for Linux (x86_64)",
+      "inherits": ["environmentVars"],
       "condition": {
         "type": "equals",
         "lhs": "${hostSystemName}",
@@ -116,6 +133,7 @@
       "name": "windows-x64",
       "displayName": "Windows x64",
       "description": "Default Windows build (x64)",
+      "inherits": ["environmentVars"],
       "condition": {
         "type": "equals",
         "lhs": "${hostSystemName}",
@@ -128,6 +146,7 @@
         "OBS_CMAKE_VERSION": {"type": "STRING", "value": "3.0.0"},
         "ENABLE_BROWSER": true,
         "VIRTUALCAM_GUID": {"type": "STRING", "value": "A3FCE0F5-3493-419F-958A-ABA1250EC20B"},
+        "GPU_PRIORITY_VAL": {"type": "STRING", "value": "$penv{GPU_PRIORITY_VAL}"},
         "ENABLE_CCACHE": false
       }
     },