Support SKIP LOCKED with FOR SHARE in Postgres

[matgr1]

Feature Description

#5927 added support for SKIP LOCKED with FOR UPDATE but not with FOR SHARE - can this also be added as pessimistic_partial_read for FOR SHARE?

The Problem

There is no way to specify FOR SHARE SKIP LOCKED

The Solution

Add a new mode for setLock pessimistic_partial_read that is only supported by Postgres (similar to #5927) that translates to FOR SHARE SKIP LOCKED

Considered Alternatives

Additional Context

we currently work around this with the following hack:

		const [sql, params] = query.getQueryAndParameters();
		const fullSql = `${sql} SKIP LOCKED`;
		const result = await entityManager.query(fullSql, params);

and then using the strategy here to map the results to an entity

Relevant Database Driver(s)

DB Type	Relevant
aurora-mysql	no
aurora-postgres	no
better-sqlite3	no
cockroachdb	no
cordova	no
expo	no
mongodb	no
mysql	no
nativescript	no
oracle	no
postgres	yes
react-native	no
sap	no
spanner	no
sqlite	no
sqlite-abstract	no
sqljs	no
sqlserver	no

Are you willing to resolve this issue by submitting a Pull Request?

• ✖️ Yes, I have the time, and I know how to start.
• ✖️ Yes, I have the time, but I don't know how to start. I would need guidance.
• ✖️ No, I don’t have the time, but I can support (using donations) development.
• ✖️ No, I don’t have the time and I’m okay to wait for the community / maintainers to resolve this issue.
• ✅ Maybe, will try to see if I have some time soon