feat(menu): add icon support for Submenu in Rust and JS/TS APIs

[s00d]

This PR adds support for icons (custom and native) in submenus for both the Rust (tauri) and JS/TS (@tauri-apps/api) APIs.
Submenus can now display icons just like regular menu items.

• SubmenuOptions now accepts an icon field.
• The Submenu class provides setIcon and setNativeIcon methods.
• Rust API supports icon and nativeIcon for submenus via builder and methods.
• Usage examples are added to the documentation and demo app.

Closes: #11796

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• Changefile added in .changes/ (minor:enhance)
• All commits are signed
• cargo test and cargo clippy pass locally for the new code
• PR is ready for review

[github-actions]

Package Changes Through 736ebd7

There are 7 changes which include tauri-cli with minor, @tauri-apps/cli with minor, tauri-utils with minor, tauri-bundler with patch, tauri with minor, @tauri-apps/api with minor, tauri-plugin with minor

Planned Package Versions

The following package releases are the planned based on the context of changes in this pull request.

package	current	next
@tauri-apps/api	2.7.0	2.8.0
tauri-utils	2.6.0	2.7.0
tauri-bundler	2.5.2	2.5.3
tauri-runtime	2.7.1	2.7.2
tauri-runtime-wry	2.7.2	2.7.3
tauri-codegen	2.3.1	2.3.2
tauri-macros	2.3.2	2.3.3
tauri-plugin	2.3.1	2.4.0
tauri-build	2.3.1	2.3.2
tauri	2.7.0	2.8.0
@tauri-apps/cli	2.7.1	2.8.0
tauri-cli	2.7.1	2.8.0

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Read about change files or the docs at github.com/jbolda/covector

[FabianLars]

Thank you for the PR! We just released 2.6 so we'll have to keep the dev branch open for patch changes for a few days/weeks. Just so you can prepare for a bit of a delay here :)

Btw, the rust code comments aren't in english yet and your commits (expect the last 2 merge commits) aren't signed :)

[s00d]

Thank you for the PR! We just released 2.6 so we'll have to keep the dev branch open for patch changes for a few days/weeks. Just so you can prepare for a bit of a delay here :)

Btw, the rust code comments aren't in english yet and your commits (expect the last 2 merge commits) aren't signed :)

Thank you for your feedback!
I've fixed the main issues, updated the Rust code comments to English, signed my commits, and squashed everything into a single commit to keep the history clean.
No problem about the delay — I’m happy to wait as long as needed.
Thanks again, and let me know if there’s anything else I should address.

[Legend-Master]

Didn't look at the details yet, but it doesn't seem to work for me on Windows (clicked Create menu with Image icon and then Popup), is it supposed to work on Windows?

[s00d]

Didn't look at the details yet, but it doesn't seem to work for me on Windows (clicked Create menu with Image icon and then Popup), is it supposed to work on Windows?

I apologize, I overlooked that menu formation works slightly differently on Windows in the tray context, so I've created a pull request with the necessary fixes

PR #308

[Legend-Master]

Looks really good, and works for me on Windows as well now, left some comments and will do a proper review tomorrow

[s00d]

@Legend-Master Fixed your comments. Also added set_icon and set_native_icon in crates/tauri/src/menu/submenu.rs.

[Legend-Master]

Awesome work, thanks!