Issue description

useIndex is not preserved when cloning a QueryExpressionMap (or a QueryBuilder) instance

Expected Behavior

Cloning a QueryBuilder (or more specifically a QueryExpressionMap) instance via the .clone() method should preserve the useIndex property, if defined

Actual Behavior

queryBuilder.expressionMap.useIndex is not preserved, since it's not explicitly copied over in QueryExpressionMap.clone() like the other properties are

Steps to reproduce

const qb = dataSource
    .getRepository(SomeEntity)
    .createQueryBuilder("u")
    .useIndex("IDX_foo")

console.log(qb.expressionMap.useIndex) // "IDX_foo"
console.log(qb.clone().expressionMap.useIndex) // undefined

My Environment

Additional Context

No response

Relevant Database Driver(s)

• aurora-mysql
• aurora-postgres
• better-sqlite3
• cockroachdb
• cordova
• expo
• mongodb
• mysql
• nativescript
• oracle
• postgres
• react-native
• sap
• spanner
• sqlite
• sqlite-abstract
• sqljs
• sqlserver

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

Yes, I have the time, and I know how to start.