Monotonicity state moved into GenerationOptions instance making the state not globally shared

[Seramis]

Description

The state necessary for monotonic ULID generation is now part of GenerationOptions instance instead of being globally shared. This fixes potential conflicts between different monotonic options being employed with all of them sharing the same state.
Documentation is updated accordingly.
Benchmarks were not affected.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Other (please specify):

Checklist

• The PR is submitted to the correct branch (main).
• My code follows the project's coding style. (.editorconfig)
• I have commented my code, particularly in hard-to-understand areas and public interfaces.
• I have added or updated tests for the changes I made.
• All new and existing tests passed.
• I have updated the documentation where applicable.

Additional Notes

Theoretically it is a breaking change as each GenerationOptions instance holds its own state. In practice, only better performance and more reasonably expected generated ULIDs should be the result.