there are many many places where processor arch each with their own list of arches

[cyrush]

Describe the bug

When reviewing Mark's thorough PR to add arm64 arch support, I was surprised at the amount of places we have processor arch here were two of the surprises:

src/common/misc/InstallationFunctions.C

Many of these look very old and we are missing new ones (ppc64le)
I think this was used to download new versions of VisIt from the GUI.
I don't think that is supported well, so maybe we don't need this function anymore?

https://github.com/visit-dav/visit/blob/develop/src/test/tests/unit/launcher.py
In this case, maybe there isn't much to suggest. I guess we could provide a Python API call that lists all the valid archs.

Related but already resolve:

We had an issue with launch on rzansel that was due to ppc64le case missing.

[markcmiller86]

Just to be clear, all the instances I found and changed were based on textual analysis (e.g. grep) and not on any specific functionality failing other than install paths having incorrect architecture moniker. So, there is a chance that some of my changes were to obsolete or otherwise irrlevant code. It was just easier for me to fix everything I could find than try to figure out which instances correlate with which functionality.