Windows: add IconExtWindows::from_resource_name

[rctlmk]

Adds a new method, IconExtWindows::from_resource_name, on Windows. Works pretty much the same as IconExtWindows::from_resource.

• Tested on all platforms changed
• Added an entry to the changelog module if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior

[kchibisov]

Do we really need this, given that other API can be used as well?

[madsmtm]

Maybe we should instead change from_resource to take a string instead of the ordinal ID?

[rctlmk]

Since there's this resource pointer conversion thing, it would be nice to have both u16 and &str methods, I think.
Basically, if the resource file looks something like this:

app ICON "a.ico"
1 ICON "b.ico"

Icon::from_resource_name("app", None) and Icon::from_resource_id(1, None) will work, but Icon::from_resource_name("1", None) won't.

[madsmtm]

Ah, makes sense. Mind documenting this too? And e.g. link to https://learn.microsoft.com/en-us/windows/win32/menurc/icon-resource ?

[rctlmk]

Yes, good thinking.

[madsmtm]

Thanks, this is perfect