[RFE] Support user-defined lab_name for dynamic inventory and wiki

[sadsfae]

Currently people need to edit these files to change the inventory page and navigation bar header to change the lab name:

https://github.com/redhat-performance/quads/blob/latest/src/quads/web/templates/navbar.html#L2 https://github.com/redhat-performance/quads/blob/latest/src/quads/web/templates/wiki/inventory.html#L5

This RFE covers making a new conf variable called lab_name for this value so it can be more easily configurable.