add prefix in generated eager relationship queries

[jidma]

Closes #14626

When using a table name with an SQL keyword (example: Order), the generated query throws an exception:

Example:

    @Query("select distinct order from Order order left join fetch order.products")
    List<Order> findAllWithEagerRelationships();

Produces the following error:

Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected token: order near line 1, column 17 [select distinct order from com.mycompany.myapp.domain.Order order left join fetch order.products]
        at org.hibernate.hql.internal.ast.QuerySyntaxException.convert(QuerySyntaxException.java:74)
        at org.hibernate.hql.internal.ast.ErrorTracker.throwQueryException(ErrorTracker.java:93)
        at org.hibernate.hql.internal.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:301)
        at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:189)
        at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:144)
        at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:113)
        at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:73)
        at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:162)
        at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:613)
        at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:725)
        ... 71 common frames omitted

This PR adds the prefix to the instance name in such case (order -> jhiOrder):

    @Query("select distinct jhiOrder from Order jhiOrder left join fetch jhiOrder.products")
    List<Order> findAllWithEagerRelationships();

Tested with the following jdl

entity Product {
    name String
}

entity Client {
    name String
}

entity Order {
    name String
}

entity Left {
    name String
}

relationship ManyToMany {
    Order{product(name)} to  Product{order} 
    Product{desc(name)} to  Left{product} 
    Client{product(name)} to  Product{product} 
    Left{client(name)} to Client{desc(name)} 
}

relationship ManyToOne {
    Order{user(login)} to  User
    Left{user(login)} to  User
}

---

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[mshima]

LGTM