fix(ui-mcp): revert MCP setup page redesign (#4745)

## Description

reverts #4740 and restores the mcp setup page to its prior
implementation. seems we still have some race condition or other
intermittent problem. I don't think it's worth chasing after this as we
can easily get the list at build or deploy time or do this call unauthed
as this is just a list of tools that should be public anywya.