[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.

Beginne damit, die API zur Generierung von E-Mail-Links des Java SDK und das in der Issue erwähnte EmailLinkType enum zu finden, und vergleiche dann die derzeit unterstützten Link-Typen mit der Unterstützung von generateVerifyAndChangeEmailLink im Node SDK. Erledigt ist die Aufgabe, wenn das Java SDK VERIFY_AND_CHANGE_EMAIL und eine entsprechende generateVerifyAndChangeEmailLink-Funktionalität bereitstellt und das neue Verhalten abgedeckt ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.