UI: Improve and update app CMake 3 metainfo file

CMake 2 path have a newer version of this file.

See the following commits for metainfo change details:
- 853ae5ea6e
- 904fe87f83
- 0cc6068ed4

UI/cmake/linux/com.obsproject.Studio.metainfo.xml.in

@@ -3,10 +3,12 @@
   <id>com.obsproject.Studio</id>
   <launchable type="desktop-id">com.obsproject.Studio.desktop</launchable>
   <metadata_license>CC0-1.0</metadata_license>
-  <project_license>GPL-2.0</project_license>
+  <project_license>GPL-2.0-or-later</project_license>
   <name>OBS Studio</name>
-  <developer_name>OBS Project</developer_name>
-  <summary>Live streaming and video recording software</summary>
+  <developer id="com.obsproject">
+    <name>OBS Project</name>
+  </developer>
+  <summary>Live stream and record videos</summary>
   <description>
     <p>Free and open source software for video capturing, recording, and live streaming.</p>
     <p>Features:</p>
@@ -30,17 +32,37 @@
   <url type="bugtracker">https://github.com/obsproject/obs-studio/issues</url>
   <url type="donation">https://obsproject.com/contribute</url>
   <url type="translate">https://crowdin.com/project/obs-studio</url>
+
+  <recommends>
+    <internet>always</internet>
+    <control>pointing</control>
+    <control>keyboard</control>
+  </recommends>
+
+  <supports>
+    <internet>offline-only</internet>
+    <control>touch</control>
+  </supports>
+
   <screenshots>
     <screenshot type="default">
-      <image>https://obsproject.com/assets/images/OBSDemoApp2610.png</image>
+      <image>https://obsproject.com/assets/images/OBSDemoApp301Flathub.png</image>
+      <caption>The OBS Studio window showing a card game, the project website, a video, and a purple rectangle</caption>
     </screenshot>
   </screenshots>
+
+  <branding>
+    <color type="primary">#284cb8</color>
+  </branding>
+
   <content_rating type="oars-1.1"/>
-  <kudos>
-    <kudo>ModernToolkit</kudo>
-    <kudo>HiDpiIcon</kudo>
-  </kudos>
+
   <releases>
-    <release version="@OBS_VERSION@" date="@APPDATA_RELEASE_DATE@"/>
+    <release version="@OBS_VERSION@" date="@APPDATA_RELEASE_DATE@">
+      <url type="details">https://github.com/obsproject/obs-studio/releases/tag/@OBS_VERSION@</url>
+    </release>
   </releases>
+  <custom>
+    <value key="flathub::manifest">https://github.com/obsproject/obs-studio/blob/@GIT_HASH@/build-aux/</value>
+  </custom>
 </component>

UI/cmake/os-linux.cmake

@@ -22,9 +22,21 @@ if(NOT DEFINED APPDATA_RELEASE_DATE)
   endif()
 endif()
 
-configure_file(cmake/linux/com.obsproject.Studio.appdata.xml.in com.obsproject.Studio.appdata.xml)
+if(NOT DEFINED GIT_HASH)
+  if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+    execute_process(
+      COMMAND git rev-parse HEAD
+      OUTPUT_VARIABLE GIT_HASH
+      WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+      OUTPUT_STRIP_TRAILING_WHITESPACE)
+  else()
+    set(GIT_HASH "master")
+  endif()
+endif()
 
-install(FILES "${CMAKE_CURRENT_BINARY_DIR}/com.obsproject.Studio.appdata.xml"
+configure_file(cmake/linux/com.obsproject.Studio.metainfo.xml.in com.obsproject.Studio.metainfo.xml)
+
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/com.obsproject.Studio.metainfo.xml"
         DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/metainfo")
 
 install(FILES cmake/linux/com.obsproject.Studio.desktop DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/applications")