Add support for updating existing files also on the cloud

See merge request !77

Add code to re-open the last segment in a cloud file. Add unit tests for update on cloud both at the FileADT level and at the IZgyWriter level.

Kvamme62/zgycopyc misc

See merge request !76

Sync with internal devops

See merge request !75

Scanning in Veracode takes a significant amount of time, so it is not carried out for all builds due to limited resources.

1. All Python code is scanned.
2. All sources needed for the Windows build (scanning takes less time).
3. The results are not imported because the validation takes over an hour (time limit for job execution)
4. Since the check takes a lot of time and restarting at a time when the previous scan has not finished will result in an error I scheduled it for once a week.
5. Vulnerabilities found in the code will not affect the "success" of the job (failBuildOnPolicyFail parameter)

Move more figures out of the top level doc folder.

See merge request !74

Reduce compiler warnings. And other cleanup.

See merge request !73

Incremental rebuild of low resolution data

See merge request !72

Increase size of one of the test files so I can use it for testing incremental builds. Needs to be large enough to leave some clean bricks.