Logical Data Replication Does Not Support External Process Multitenancy

When running on external process tenants, LDR fails with an error that looks like:

```
I241111 14:48:19.864630 7239 jobs/registry.go:1599 [T10,Vcluster-10,nsql1] 768 REPLICATION STREAM PRODUCER job 1019956658274861057: stepping through state running
...
I241111 14:48:19.909567 7446 ccl/crosscluster/logical/logical_replication_job.go:611 [T10,Vcluster-10,nsql1,job=LOGICAL REPLICATION id=1019956658305499137] 820 hit retryable error subscription: ERROR: job with ID 1019956658274861057 does not exist (SQLSTATE XXUUU)
...
```

This error occurs because [DistSQLPlanner.GetSQLInstanceInfo](https://github.com/cockroachdb/cockroach/blob/2f324cc1bbd12dd54018805a0ddbf2b2b8a98e18/pkg/sql/distsql_physical_planner.go#L254) is using an API that only returns information about KV nodes.

So at a high level what is happening is:
1. LDR connects to the remote tenant to get a plan for replication.
2. The remote tenant maps spans to sql instances and returns addresses for kv nodes instead of the sql servers.
3. The LDR client attempts to dial the KV nodes. The KV cluster is missing the LDR event producer job, so the job gets stuck in a loop.

Here's a minimal diff that allows LDR to work in external process tenants.

```
diff --git a/pkg/sql/distsql_physical_planner.go b/pkg/sql/distsql_physical_planner.go
index 7f0ccf565c3..36d13477874 100644
--- a/pkg/sql/distsql_physical_planner.go
+++ b/pkg/sql/distsql_physical_planner.go
@@ -51,6 +51,7 @@ import (
"github.com/cockroachdb/cockroach/pkg/sql/sqlerrors"
"github.com/cockroachdb/cockroach/pkg/sql/sqlinstance"
"github.com/cockroachdb/cockroach/pkg/sql/types"
+ "github.com/cockroachdb/cockroach/pkg/util"
"github.com/cockroachdb/cockroach/pkg/util/encoding"
"github.com/cockroachdb/cockroach/pkg/util/hlc"
"github.com/cockroachdb/cockroach/pkg/util/intsets"
@@ -251,7 +252,17 @@ func (dsp *DistSQLPlanner) GetAllInstancesByLocality(
func (dsp *DistSQLPlanner) GetSQLInstanceInfo(
sqlInstanceID base.SQLInstanceID,
) (*roachpb.NodeDescriptor, error) {
- return dsp.nodeDescs.GetNodeDescriptor(roachpb.NodeID(sqlInstanceID))
+ instance, err := dsp.sqlAddressResolver.GetInstance(context.Background(), sqlInstanceID)
+ if err != nil {
+ return nil, err
+ }
+ return &roachpb.NodeDescriptor {
+ SQLAddress: util.UnresolvedAddr {
+ NetworkField: "tcp",
+ AddressField: instance.InstanceSQLAddr,
+ },
+ Locality: instance.Locality,
+ }, nil
}
```

Jira issue: CRDB-44283