Add full support for Mac-specific keyboard layouts (#736)

* IPP for Mac, flawed initial experiments

* Cleanup and progress, but not compiling yet

* Fix error and rename nonmac -> standard

* Extentd ipp macros to accomodate mac input

* Add Mac versions of shortcuts; refactor and document the input mapper macros

* Change frontend styling for user input labels in floating menus

* Additional macro documentation

* A little more documentation

* Improve entry macro syntax

* Move input mapper macros to a separate file

* Adapt the keyboard shortcuts to the user's OS

* Display keyboard shortcuts in the menu bar based on OS

* Change Input Mapper macro syntax from {} to ()

* Fix esc key bug in Vue

* Tweaks

* Interim solution for Mac-specific hints

* Feed tooltip input hotkeys from their actions

* Fix hotkeys for tools because of missing actions

* Make Vue respect Ctrl/Cmd differences per platform

* Remove commented lines

* Code review pass by me

* Code review suggestions with TrueDoctor

* Turn FutureKeyMapping struct into ActionKeys enum which is a bit cleaner

* Add serde derive attributes for message discriminants

* Re-add serde deserialize

* Fix not mutating ActionKeys conversion; remove custom serializer

* Add serde to dev dependencies

Co-authored-by: Dennis <dennis@kobert.dev>

editor/src/document/portfolio_message_handler.rs

@@ -1,4 +1,5 @@
 use super::clipboards::{CopyBufferEntry, INTERNAL_CLIPBOARD_COUNT};
+use super::utility_types::Platform;
 use super::{DocumentMessageHandler, MenuBarMessageHandler};
 use crate::consts::{DEFAULT_DOCUMENT_NAME, GRAPHITE_DOCUMENT_VERSION};
 use crate::dialog;
@@ -23,6 +24,7 @@ pub struct PortfolioMessageHandler {
 	active_document_id: Option<u64>,
 	copy_buffer: [Vec<CopyBufferEntry>; INTERNAL_CLIPBOARD_COUNT as usize],
 	font_cache: FontCache,
+	pub platform: Platform,
 }
 
 impl PortfolioMessageHandler {
@@ -473,6 +475,7 @@ impl MessageHandler<PortfolioMessage, &InputPreprocessorMessageHandler> for Port
 				responses.push_back(MovementMessage::TranslateCanvas { delta: (0., 0.).into() }.into());
 			}
 			SetActiveDocument { document_id } => self.active_document_id = Some(document_id),
+			SetPlatform { platform } => self.platform = platform,
 			UpdateDocumentWidgets => {
 				if let Some(document) = self.active_document() {
 					document.update_document_widgets(responses);