feat(build): add API to update the iOS entitlements file

[lucasfernog]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• New Binding issue #___
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes, and the changes were approved in issue #___
• No

Checklist

• When resolving issues, they are referenced in the PR's title (e.g fix: remove a typo, closes #___, #___)
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary

Other information

[lucasfernog]

Needs #7445 and #7446

[lucasfernog]

Example usage together with #7447

// Copyright 2019-2023 Tauri Programme within The Commons Conservancy
// SPDX-License-Identifier: Apache-2.0
// SPDX-License-Identifier: MIT

#[derive(serde::Deserialize)]
struct Config {
    domains: Vec<String>,
}

fn main() {
    if let Some(config) = tauri_build::config::plugin_config::<Config>("deepLink") {
        #[cfg(target_os = "macos")]
        {
            tauri_build::mobile::update_entitlements(|entitlements| {
                entitlements.insert(
                    "com.apple.developer.associated-domains".into(),
                    config
                        .domains
                        .into_iter()
                        .map(Into::into)
                        .collect::<Vec<_>>()
                        .into(),
                );
            })
            .expect("failed to update entitlements");
        }
    }
}