feat: Customizable shortcuts/hotkeys (#439)

This implements the logic for allowing hotkeys with modifiers.
Implemented globalhotkeys and videocontrol hotkeys
Also implements saving the forward backwards seconds to the user.

Co-authored-by: PartyDonut <PartyDonut@users.noreply.github.com>

lib/l10n/app_en.arb

@@ -1139,7 +1139,7 @@
   },
   "noVideoPlayerOptions": "The selected backend has no options",
   "mdkExperimental": "MDK is still in a experimental stage",
-  "skipButtonLabel": "(S)kip {segment}",
+  "skipButtonLabel": "Skip {segment}",
   "@skipButtonLabel": {
     "placeholders": {
       "segment": {
@@ -1292,5 +1292,29 @@
   "syncAllFiles": "Sync all files",
   "usePostersForLibraryIconsTitle": "Show posters for library icons",
   "usePostersForLibraryIconsDesc": "Show posters instead of icons for libraries",
-  "offline": "Offline"
+  "offline": "Offline",
+  "shortCuts": "Shortcuts",
+  "skipForwardLength": "Skip forward length",
+  "skipBackLength": "Skip back length",
+  "playPause": "Play/Pause",
+  "seekForward": "Seek Forward",
+  "seekBack": "Seek Back",
+  "mute": "Mute",
+  "volumeUp": "Volume Up",
+  "volumeDown": "Volume Down",
+  "nextVideo": "Next Video",
+  "prevVideo": "Previous Video",
+  "nextChapter": "Next Chapter",
+  "prevChapter": "Previous Chapter",
+  "fullScreen": "Full Screen",
+  "skipMediaSegment": "Skip Media Segment",
+  "exit": "Exit",
+  "shortCutAlreadyAssigned": "Shortcut '{hotKey}' already assigned",
+  "@shortCutAlreadyAssigned": {
+    "placeholders": {
+      "hotKey": {
+        "type": "String"
+      }
+    }
+  }
 }