[FEA] Add ability to build containers that default to a user other than root.

[drobison00]

Is your feature request related to a problem? Please describe.
Yes. The primary issue, is that by default containers use the 'root' user. In addition to the baseline security concerns this can present, it also induces some inconvenient behavior and side effects. Specifically, if I run a container as myuser with a user id of 1234 and mount my working directory into the container, then all files created by the container in the mounted directory will have root ownership. This can cause a variety of subtle problems and degraded user experience.

Describe the solution you'd like
When running a Morpheus container an end user should be able to specify the UID they want the tasks in the container to run under.

Describe alternatives you've considered
No other alternatives considered

Additional context

There are some complicating issues with user permissions on base conda installation items, packages, etc.. which make this more complicated than I'd originally hoped and why its on the back log. I don't think there are any insurmountable problems, but it might require some trail and error to work out all the issues.