v0.7.0 Preview to Q-score and `dfit` cmd

Key summary

• Q-score is now integrated (a GPU version) into DiffFit. Thanks to the hint from Guillaume Gaullier to me in the ChimeraX Users Help chimerax-users@cgl.ucsf.edu email list.
• Cmd: dfit, dfit disk, dfit path; they run for the nogui mode. Thanks to the suggestion from @tomgoddard.
  • dfit #1 in #2
  • dfit disk strDir <subunits cif/pdb> inMap <map file> level <float>
  • dfit path show <result folder, e.g., DiffFit_out/disk>
  • dfit path vol <result folder> new <e.g., new local path to the map>
  • dfit path mol <result folder> old_path <e.g., path on server> new_path <e.g. path on local PC>
  • help dfit
• Sim maps are now moved to the structures folder; q shells (for Q-scores) are also stored in the structures folder.
• Generate q shells section under the Utilities tab. Only the Full (non-overlapping) is in effect.
• New columns/metrics in the View tab fit results table: Mol name, Q-score, # Atoms, Avg density (in) for inside atoms, Avg density (all), DF CID
• The DF CID metric is a combined metric computed from Correlation, Inside, and Avg Density (all).
• In practice, I feel the important metrics are Q-score, Density (normalized), and Inside. Thus, I am planning to remove all other metrics to speed up the computation further unless I receive feedback or notice cases where the other metrics become better than the mentioned three. You may give your feedback at https://github.com/nanovis/DiffFit/issues.
• The whole running should be a bit faster now. Thanks to the help from @tomgoddard for the clustering speedup in #44.
• Up and down keys now work inside the View tab fit results table.
• Under the View tab, below the table, there are now Candidates Folder and Candidates id to save multiple candidates at once.
• Candidates id will likely be automatically generated when many fits pass the threshold.
• Automatically view orient after fitting

What's Changed

• Add dependencies' versions by @RodenLuo in #39
• Pip manager by @RodenLuo in #41
• GPU Q-scores and dfit cmd preview and misc by @RodenLuo in #45

Full Changelog: v0.6.2...v0.7.0