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>

proc-macros/src/discriminant.rs

@@ -112,8 +112,16 @@ pub fn derive_discriminant_impl(input_item: TokenStream) -> syn::Result<TokenStr
 			)
 		})
 		.unzip::<_, _, Vec<_>, Vec<_>>();
+	#[cfg(feature = "serde-discriminant")]
+	let serde = quote::quote! {
+		#[derive(serde::Serialize, serde::Deserialize)]
+	};
+
+	#[cfg(not(feature = "serde-discriminant"))]
+	let serde = quote::quote! {};
 
 	let res = quote::quote! {
+		#serde
 		#discriminant
 
 		impl ToDiscriminant for #input_type {