feat: sshnpd: add --storage-path option

[gkc]

- What I did

• Allow user to specify a path for where the sshnpd program keeps any locally stored data

- How I did it

• See commits

- How to verify it

• Automated tests pass
• Manual tests pass - verifiable by checking that the provided storage-path contains the hive boxes once the sshnpd process has started up. Manually tested successfully as follows:
  • bin/sshnpd -a @daemonAtSign -m @clientAtSign -d mbp -v -s -u --storage-path ./sshnpd_storage/@daemonAtSign
  • bin/sshnp -f @clientAtSign -t @daemonAtSign -d mbp -i ~/.ssh/noports -h @rv_eu -s noports.pub -u @USER --idle-timeout 30 --ssh-client dart

- Description for the changelog
feat: sshnpd: add --storage-path option

[gkc]

@cconstab please can you re-review when you get a moment - thanks!

[cconstab]

We used to have the files in a temp directory so you could run concurrent sshnp without box problems. Just looking at the change here have we lost that or am I missing something ?

[cconstab]

We used to have these files in a temp directory so you could run concurrent sshnp without hive box problems. Just looking at the change here have we lost that or am I missing something ?

[gkc]

We used to have these files in a temp directory so you could run concurrent sshnp without hive box problems. Just looking at the change here have we lost that or am I missing something ?

This is a change to sshnpd, not sshnp

[gkc]

We used to have these files in a temp directory so you could run concurrent sshnp without hive box problems. Just looking at the change here have we lost that or am I missing something ?

This is a change to sshnpd, not sshnp

But that sshnp feature may well have vanished sometime in the past few months