Refactor nexus writer

[Modularius]

Summary of changes

• Added thiserror style error handling removing over-reliance on anyhow. The code now conforms to ADR 7. Standardise error handling.
• Added traits to extend functionality for hdf5::{Group, Dataset, Attribute} in hdf5_writer.rs.
• Error handling includes a hdf5 path where appropriate to enable better locality, and a Location field in non-hdf5 related errors.
• More standardised handling of runlogs/selogs/alarms. All logs contain a time Dataset with a "units" and "start" attribute, where "start" denotes the RFC3999 date/time to which the time value is relative to.

Instruction for review/testing

• General code review.
• Has been tested on simulated data as well as on live HiFi data.

[DanNixon]

Looks good.

A couple of other things that might as well be done now:

• Could the term "run file" be revisited. This does not really seem to describe the thing it actually refers to (a separate file describing a run vs. a collection of run metadata).
• Could crate::hdf5_file::run_file_components be moved to crate::hdf5_file::run_file::components?

[Modularius]

The RunFile struct does contain the hdf5::File struct as well as the RunFileContents struct abstracting the file's contents. You might be thinking of the RunParameters which does largely just contain the metadata.

This PR is the first in a couple I've got planned which will, among other things make the naming conventions more logical. It's probably okay to leave run_file_components as is for now, as it might not exist in the next one.

[DanNixon]

👍