`filewriter`: static metadata

The filewriter must be able to write the 'static' metadata for a run.

These are pieces of metadata which only require knowledge of the `runStart` and `runStop` messages. This assumes that the run start is emitted with appropriate metadata to enable this data to be written.

This includes:
- `raw_data_1/beamline`
- `raw_data_1/definition`
- `raw_data_1/definition_local`
- `raw_data_1/duration`
- `raw_data_1/end_time`
- `raw_data_1/experiment_identifier` (RB number)
- `raw_data_1/measurement/first_run`
- `raw_data_1/measurement/id`
- `raw_data_1/measurement/label`
- `raw_data_1/measurement/subid`
- `raw_data_1/measurement/type`
- `raw_data_1/measurement_first_run`
- `raw_data_1/measurement_id`
- `raw_data_1/measurement_label`
- `raw_data_1/measurement_subid`
- `raw_data_1/measurement_type`
- `raw_data_1/name`
- `raw_data_1/notes`
- `raw_data_1/program_name`
- `raw_data_1/run_cycle`
- `raw_data_1/run_number`
- `raw_data_1/sample/distance`
- `raw_data_1/sample/height`
- `raw_data_1/sample/id`
- `raw_data_1/sample/name`
- `raw_data_1/sample/shape`
- `raw_data_1/sample/thickness`
- `raw_data_1/sample/type`
- `raw_data_1/sample/width`
- `raw_data_1/script_name`
- `raw_data_1/seci_config`
- `raw_data_1/start_time`
- `raw_data_1/title`
- `raw_data_1/user_1/affiliation`
- `raw_data_1/user_1/name`

## Potential differences from existing files

- `program_name` will no longer be `ISISICP.exe` and will be the name of the filewriter executable.

Start by locating the filewriter and its runStart/runStop message handling, then compare how existing files write metadata. Implement support for the listed static metadata, including the executable name for program_name, and verify that all values available from runStart and runStop are written.

Vom Indexierungsmodell aus dem Issue-Text verfasst.