Cleanup, clock, more guards and PHP 8.4 support

• Breaking change: Removed deprecated isDate* methods from Moment.
• Breaking change: Dropped custom normalizers in favor of digital-craftsman/self-aware-normalizers.
• Breaking change Dropped support for PHP 8.2.
• Added Clock implementation with SystemClock and FrozenClock.
• Added guard methods for comparison methods to Moment, Date and Time like mustBeEqualTo with option to throw custom exception.
• Changed normalization of Moment to include microseconds.
• Added support for PHP 8.4.