[FEATURE] Allow specifying available display modes per connection (and other client capabilities)

# Feature

Allow specifying which available display modes the MCP client advertises to the server (possibly as an advanced option when setting up the server).

Can be extended to configure client capabilities more generally. Would be nice to see the different sever handling for clients with different capabilities. (e.g. verifying that server does not send down MCP metadata for clients that do not advertise MCP apps capability)

# Additional Context

E.g. some server MCP apps will want to hide a "fullscreen button" when "fullscreen" is not an advertised display mode in `availableDisplayModes`. There is no real way to test this in MCPJam as of today.