Add clear indication of security on the MCP Server listings in the Expert Resource Selector

### Description

As part of https://github.com/FlowFuse/flowfuse/pull/6549 it was discussed and determined that basic auth will not be supported at this time.

That leaves us with the question how do we let users know this at the point of use.

Following a Eng meeting it was suggested that the resource selector could (should) inform the user at the point of use whether an MCP Server is secured or not (good for the end user). Then, we could (conditionally) include the Basic Auth servers in the Resources selector list as disabled/unselect-able servers - giving users foresight and knowledge of why the MCP Server is not present!

@dimitrieh tagging you in case you need to organise / tag this item.

### Epic/Story

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate