catalog/lease: setting to support consistent view of descriptors transactions

[fqazi]

Currently when a transaction uses multiple descriptors its possible for it to observe different versions of dependent descriptors. For example if we have a schema change that publishes descriptor A and B with V+1, we currently can have a transaction observe descriptors A ( version V), and B ( version V1) on divergent versions. This is not ideal if we want leased descriptors to back crdb_internal functions. To address this, we are going to modify descriptor leasing to use timestamps that are guaranteed to provide a consistent view.

Jira issue: CRDB-54515

Epic CRDB-48806