Route Servers: Support 'depends_on' for routeServerBGPConnection

[ninjarobot]

The changes in this PR are as follows:

• Route Servers: Support 'depends_on' for routeServerBGPConnection

I have read the contributing guidelines and have completed the following:

• [x] Tested my code end-to-end against a live Azure subscription.
• [x] Updated the documentation in the docs folder for the affected changes.
• [x] Written unit tests against the modified code that I have made.
• [x] Updated the release notes with a new entry for this PR.
• [x] Checked the coding standards outlined in the contributions guide and ensured my code adheres to them.

If I haven't completed any of the tasks above, I include the reasons why here:

Below is a minimal example configuration that includes the new features, which can be used to deploy to Azure:

routeServer {
    name "my-route-server"
    link_to_vnet "my-vnet"
    add_bgp_connections [
        routeServerBGPConnection {
            name "elf01"
            peer_ip "100.72.3.4"
            peer_asn 12345
        }
        routeServerBGPConnection {
            name "elf02"
            peer_ip "100.72.3.5"
            peer_asn 12345
            depends_on (ResourceId.create(Farmer.Arm.Network.routeServerBGPConnections, ResourceName "my-route-server", ResourceName "elf01"))
        }
    ]