Merge branch `Davi0kProgramsThings:feature/improvements` into branch `bitfinexcom:v3-beta`.

[Davi0kProgramsThings]

Description

PR includes some pre-release changes to further improve v3.0.0b1.

These introduce new features, improvements and bug fixes to v3-beta, such as:

• allowing users to define a timeout in seconds after which the client should crash if it has been offline for too long.
• emitting on_disconnection when the connection with the server closes; users should perform disposal activities here.
• deleting BfxWebSocketClient::once to improve user experience and avoid confusion about registering to events.
• and much more.

NOTE: PR also includes some breaking changes: backwards compatibility with older commits will no longer be available.

Motivation and Context

PR prepares v3.0.0b1 to its beta release. There are no more pending features, improvements and bug fixes. bitfinex-api-py is now stable enough for users to start using it in their projects.

Related Issue

PR fixes the following issue: -

Type of change

• [X] Bug fix (non-breaking change which fixes an issue);
• [X] New feature (non-breaking change which adds functionality);
• [X] Breaking change (fix or feature that would cause existing functionality to not work as expected);
• [ ] This change requires a documentation update;

Checklist:

• [X] My code follows the style guidelines of this project;
• [X] I have performed a self-review of my code;
• [X] I have commented my code, particularly in hard-to-understand areas;
• [ ] I have made corresponding changes to the documentation;
• [X] My changes generate no new warnings;
• [X] I have added tests that prove my fix is effective or that my feature works;
• [X] New and existing unit tests pass locally with my changes;
• [X] Mypy returns no errors or warnings when run on the root package;
• [X] Pylint returns a score of 10.00/10.00 when run on the root package;
• [ ] I have updated the library version and updated the CHANGELOG;