nexus-db-queries: replace BgpPeerConfig with BgpPeerFromDb

[jgallagher]

The BgpPeerConfig exported by nexus-db-queries was a type that contained mostly database-flavored types (SqlU16 and friends) but had most of the same fields as the external API's BgpPeer type (while having no relation to the external API's BgpPeerConfig). This change replaces the datastore BgpPeerConfig with BgpPeerFromDb, which wraps an external API BgpPeer and adds the two extra fields we need in the sync_switch_configuration background task.

The rest of the changes are fallout from that; mostly we get to get rid of a lot of .map(|x| x.0) or .map(From::from) conversions that the bg task had to do to go from "database-flavored types" to "API-flavored types".

Part of #9832.

[jgallagher]

It looks like the test failing in CI is because these two disagree on the value of interface_name:

interface_name: Name("qsfp0")
interface_name: Name("phy0")

I don't think I changed the behavior here - it looks like the test as written before omitted checking this field. Was that intentional, and there's a reason they're different? Or is the fact that they're different a bug that's just now surfacing?

[jgallagher]

I think this mismatch is also present on main. SwitchPortBgpPeerConfig takes an explicit interface_name: Name argument:

omicron/nexus/db-model/src/switch_port.rs

Lines 780 to 786 in afe86cb

	impl SwitchPortBgpPeerConfig {
	pub fn new(
	port_settings_id: Uuid,
	bgp_config_id: Uuid,
	interface_name: Name,
	p: &networking_types::BgpPeer,
	) -> Self {

and it ignores p.interface_name (the interface name inside the networking_types::BgpPeer it's given). When we call this from do_switch_port_settings_create(), we pass the link_name, not the interface_name:

omicron/nexus/db-queries/src/db/datastore/switch_port.rs

Lines 1503 to 1508 in afe86cb

	bgp_peer_config.push(SwitchPortBgpPeerConfig::new(
	psid,
	bgp_config_id,
	peer_config.link_name.clone().into(),
	p,
	));

That explains why when we query this BGP config back after inserting it, we see an interface name of phy0 (the link name), not qsfp0 (the interface name inside the BgpPeer struct, which is ignored AFAICT).

I don't know what to make of this, though. Bug? Not bug just surprising behavior? More complex than either of those?