Adding In-Band Registration (XEP-0077) with Fundamental Changes

[vsevex]

Introduced In-Band Registration (XEP-0077) mechanism in this commit. For more information about this extension please refer to the branch named registration and take a look at the changes and opened issues.

In this commit, there are several changes to the fundamental work structure of the Echo package. Prepared groundwork for documentation that will be available soon in the corresponding branch.

Why This is Important:

• The addition of the In-Band Registration Extension enhances the user experience by enabling account creation within the Echo client. This feature simplifies onboarding for new users and streamlines the registration process.

Breaking:

• Changed the version variable which is the main part of the initial IQ stanza request. When testing took steps on the Ejabberd server, the server responded error stanza due to the version. Changed to version 1.0 to make the package work properly.
• Changed the _password type to the String only. Due to that was part of Scram authentication, there was not any huge difference between passing Map and String to the constructor. If there will be any need for the Map type password to the constructor due Salted Challenge Response Authentication Mechanism, that can be implemented in future updates.
• The work structure of the several methods changed for the in-band registration process. For further information, please refer to the corresponding commit.

Next Steps:

• As of now, there is no detailed documentation available for the changes made. However, it will be provided in the corresponding branch soon.