Provide a no-concatenation option

[gold2718]

Add a new exclusive concatenation option (currently --monthly, --yearly, or --merge-all) that would not attempt any concatenation.
Suggest option is --compress-only.
This option would compress each NetCDF file for the chosen components but do no merging.

Suggested by @matsbn

[gold2718]

From the 2024-03-21 NorESM core meeting:

Should the rcat_noresm.sh script have different default settings for different components? Currently, the options (and proposed option) mentioned above would apply to all components specified in each run (with --yearly being the default for all components). It would be useful to get input from post-processing users to find out if other defaults and/or configuration options would be beneficial.