[ENHANCEMENT] Grey out jobs that can't be run for the selected trajectory.

**Is your feature request related to a problem? Please describe.**
Some trajectories will not work for specific jobs. For example, when a trajectory does not have a unit cell a density job will fail. Currently, we allow the user to run the job but it will crash and give the user an error message about why the job failed.

**Describe the solution you'd like**
We should be able to determine beforehand that the job will crash. Let's gray out the job so that it can't be run when the trajectories don't have the required properties and provide some information to the user about why the trajectory can't run that job.

Start by tracing the job-selection UI and the validation or execution paths that determine whether a trajectory has the properties a job requires. Identify the required properties for each job, then verify that incompatible jobs are disabled and that the user sees why; the issue names no files or tests, so locating those entry points is part of the work.

Written by the indexing model from the issue text.