Add a direct sub classes data structure to the Painless lookup

[jdconrad]

This change has two main components.

The first is to have method/field resolution for compile-time and run-time use the same code path for now. This removes copying of member methods between super and sub classes and instead does a resolution through the class hierarchy. This allows us to correctly implement the next change.

The second is a data structure that allows for the lookup of direct sub classes for all allow listed classes/interfaces within Painless.

Given there can be gaps within sub classes due to how allow listing is specified, a subclass may propagate to the nearest allow listed subclass.

Example:

class A {} // allowed
class B extends A {} // disallowed
class C extends B {} // allowed

In this case A has C as a direct sub class.

Example:

interface A {} // allowed
class B implements A {} // disallowed
class C extends B {} // allowed

In this case A has C as a direct sub class.

Interfaces work the same way to propagate across any gaps in allow listing.

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[stu-elastic]

Looks good, just a few comment requests.

[jdconrad]

@stu-elastic Thanks for the review. I addressed your comments, and I will commit once CI passes.

[elasticsearchmachine]

💔 Backport failed

Status	Branch	Result
❌	7.x	Commit could not be cherrypicked due to conflicts

To backport manually run backport --upstream elastic/elasticsearch --pr 76955