[FR] Support generateVerifyAndChangeEmailLink

**Is your feature request related to a problem? Please describe.**

I have a Spring Boot application for which I use Firebase Admin SDK installed from Maven, version 9.7.0.

As I'd like to send to my users custom email templates regarding email confirmation, password reset and others. To do that I have to use link generation methods that SDK provides and then include that link in custom templates.

I noticed, that latest version of SDK does not support generating email links for changing user e-mail address
i.e. **generateVerifyAndChangeEmailLink**, that seems to be already supported for example in Node SDK.

Supported link types in SDK as of now:
```
static enum EmailLinkType {
VERIFY_EMAIL,
EMAIL_SIGNIN,
PASSWORD_RESET;
}
```

I believe VERIFY_AND_CHANGE_EMAIL also might be useful alongside with supporting methods.

**Describe the solution you'd like**
Add support for generateVerifyAndChangeEmailLink with VERIFY_AND_CHANGE_EMAIL.

**Describe alternatives you've considered**
I believe as an alternative it might be possible to create API calls from scratch though I believe having dedicated methods is better and easier for developers.

まず、Java SDK のメールリンク生成 API と issue で言及されている EmailLinkType enum を見つけ、既存のサポート対象リンクタイプと Node SDK の generateVerifyAndChangeEmailLink のサポートを比較します。Java SDK が VERIFY_AND_CHANGE_EMAIL と対応する generateVerifyAndChangeEmailLink 機能を公開し、新しい動作をカバレッジで確認できれば完了です。

索引モデルが issue の本文から書いたものです。