Prevent unnecessary repeated partitioning

[dafyddstephenson]

As part of #158 , several PRs have been opened to better track files handled by C-Star and prevent unnecessary repetition of potentially expensive steps:

• InputDataset file management improvements #209 caches file hashes for files obtained by InputDataset.get() to prevent them being fetched multiple times
• AdditionalCode hash tracking #211 does the same for AdditionalCode
• Check for existing compilation before compiling code #213 prevents Component.build() from compiling already compiled executables where it is clear the source code has not changed
• Persist Case instances between sessions #212 removes the need to run Case.setup() again after exiting a python session

These cover the Case.setup() and Case.build() methods, but Case.pre_run() will still start from scratch any time it is called.

After merging #209 and #210 , we should add tracking for files produced by partition and introduce a check in ROMSInputDataset.partition that skips over unnecessary regeneration of already partitioned files.

[github-actions]

This issue has been linked to Jira story CW-596.