Fix Workspace Path Configuration in Setup

[michaelmckinsey1]

Description

• Because we create the workspace directory from experiment --dest and system --dest, we must consider the case where the user provides absolute path for these. This PR makes a change where absolute paths and relative paths will result in the same workspace directory. The common path between the experiment, system, and workspace directories is only used once.
• Example shown here WIP: Add Lanl CTS-2 system rocinante to system definitions #1006 (comment)

Adding/modifying core functionality, CI, or documentation:

• Update lib/benchpark/cmd/setup.py

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.13%. Comparing base (0fd5941) to head (8c3a9df).
⚠️ Report is 6 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1007      +/-   ##
===========================================
+ Coverage    65.08%   65.13%   +0.04%     
===========================================
  Files           44       44              
  Lines         3148     3152       +4     
  Branches       237      237              
===========================================
+ Hits          2049     2053       +4     
  Misses        1092     1092              
  Partials         7        7              

Files with missing lines	Coverage Δ
lib/benchpark/cmd/setup.py	93.51% <100.00%> (+0.24%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.