[Testing]: Test workflows rather than zstash commands

[forsyth2]

Request criteria

• I searched the zstash GitHub Discussions to find a similar question and didn't find it.
• I searched the zstash documentation.
• This issue does not match the other templates (i.e., it is not a bug report, documentation request, feature request, or a question.)

Issue description

Currently, tests are divided up as create, update, etc. tests. It may make more sense and be easier to follow if we test whole workflows (e.g., create > check > ls > extract with hpss as none, as NERSC HPSS, as Globus).

[forsyth2]

This is actually an extension of the tests2 directory introduced in #348. tests2 might be better named tests_integration since it's testing the integration of commands (i.e., integration tests) rather than commands individually (i.e., unit tests)