Admin pages in k8s: Better messaging about read-only params

[artntek]

When metacat is running in k8s, the admin p0ages are accessible (with one exception - Metacat Global Properties), but if an operator tries to submit any changes, they see an error message because the properties files are non-writeable.

From a functionality perspective, this is expected and OK, since properties in k8s need to be set via the values.yaml etc.

However, from a usability point of view, it could definitely be improved, and with not too much effort. Ideas include:

• Better messaging (e.g. a banner on all pages telling the user edits must be done in values.yaml)
• Show non-editable views (i.e. display the settings as text, but not in input fields, and hide the "submit" buttons)
• Make Metacat Global Properties viewable as read-only, too (currently doesn't display at all)

Of course, these changes should only show up when running in kubernetes, not in legacy deployments

To make this slightly (but not much) more complicated, on the Replication Configuration page, values can't be edited, but buttons at bottom of page can be used successfully, since they perform actions without changing properties.
* The Update DOIs button is probably the only one needed, so we could just pull this out to a separate page if we wanted