Improve time dimension parsing

[hblitza]

Description

Related issues or pull requests

This highly speeds up the parsing of time dimension information.
It took > 7sec for 5,000 timestamps, now < 1sec.

Pull request type

• Bugfix
• Feature
• Dependency updates
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe)

Do you introduce a breaking change?

• Yes
• No

Checklist

• I have added a screenshot/screencast to illustrate the visual output of my update.
• I have added the proposed change to the CHANGELOG.md.
• I have run the test suite successfully (run npm test locally).

Thanks for co-working @hwbllmnn
@terrestris/devs please review