DbFunctions: Consider protected methods for discovering DbFunctionAttribute

[smitpatel]

At present we have set of BindingFlags to discover methods for UDFs, they explicitly ignores protected methods. But the attribute based discovery should be done regardless of protection level.
The protection level restricts user's ability to use the method inside of the EF Query but if in some way user can use it then we should translate it.
One way to use the method is to pass in IQueryable to public method in DbContext which would apply logics from protected/private methods by calling them and return it. (or there is always reflection)

[ajcvickers]

Note from triage: we should do this for any property--public, protected, internal, private.

[ajcvickers]

@pmiddleton We would love a PR for this if you are up for it. 😸

[pmiddleton]

Sounds good.

What about private and internal? Might as well find those as well while we are at it.

[smitpatel]

As @ajcvickers said above, we want all of them

[pmiddleton]

Well that would me I would have to read the whole post :)

[smitpatel]

Fixed via 843929d