Fix LocText translation handling

[jabou]

Intro

This PR is a quick hotfix for handling LocText translation in case where we have to modify the underlying Text by calling the public var text: Text property.
In the future, we can see if we can remove that property from the lib, but in that case, we will have to introduce support for setting some properties on underlying Text.

Issue

In case we use public var text: Text from the LocText directly (use-case example later), we will get the error:

This will result in a not translated LocText element (only the default language will be set; a language change will not take effect).

Fix

To fix this behavior, I replaced @Environment(\.language) base handling with completion base one. I can even remove LanguageModifier if we don't need it (not sure if someone is using it?), and we can call .onReceive directly on LocText text inside the body.
That way, when a language change occurs and a notification is fired, @State will be updated, and we will have a correct translation on the next body render.

Use Case

In case when we want to set kerning and lineSpacing on font, we have to access Text directly as those modifiers are not available on Content (e.g., creating the ViewModifier) or View (i.e., on LocText). In that case, we can use the existing public var text: Text property on which we can then apply kerning and lineSpacing. Example:

extension LocText {

    func appFont(_ fontStyle: AppFontStyle) -> some View {
        return text // returns `Text`
            .font(fontStyle.font)
            .kerning(fontStyle.style.kern) // available only on `Text`
            .lineSpacing(fontStyle.lineSpacing)
            .padding(.vertical, fontStyle.lineSpacing / 2)
    }
}

[jabou]

We will test this with the Alps Alpine regression test. If everything goes well, I'll merge and publish it.