refactor!(core): remove Icon enum and add Image type (#9011)

* refactor!(core): remove `Icon` enum and add `Image` type

* clippy

* revert api example config change

* Update image.rs

* fix build

* clippy

* change files

* add back removed methods as setter functions

* simplify error message

* Update .changes/runtime-icon-lifetime.md

* Update .changes/ico-featrue-flags.md

* Update core/tauri/src/image.rs

* update api lockfile

* update api ref

* lint

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

.changes/ico-featrue-flags.md

@@ -0,0 +1,5 @@
+---
+'tauri': 'major:breaking'
+---
+
+Renamed `icon-ico` and `icon-png` feature flags to `image-ico` and `image-png` respectively

.changes/runtime-icon-lifetime.md

@@ -0,0 +1,5 @@
+---
+'tauri-runtime': 'major:breaking'
+---
+
+Add a lifetime parameter for `Icon` type. Also changed `rgba` field to be `Cow<'a, [u8]>`

.changes/tauri-context-icon-methods.md

@@ -0,0 +1,5 @@
+---
+'tauri': 'major:breaking'
+---
+
+Removed `Context::default_window_icon_mut` and `Context::tray_icon_mut`, use `Context::set_default_window_icon` and `Context::set_tray_icon` instead. Also changed `Context::set_tray_icon` to accept `Option<T>`.

.changes/tauri-icon-removed.md

@@ -0,0 +1,5 @@
+---
+'tauri': 'major:breaking'
+---
+
+Removed `Icon` enum, use the new `Image` type instead. All APIs that previously accepted `Icon` have changed to accept `Image` instead.

.changes/tauri-image-codegen.md

@@ -0,0 +1,5 @@
+---
+'tauri-codegen': 'major:breaking'
+---
+
+Change the generated context code to use the new `Image` type in tauri.

.changes/tauri-image.md

@@ -0,0 +1,5 @@
+---
+'tauri': 'minor:feat'
+---
+
+Add `Image` type.