fix: Support httpApi authorizer with different config and function names

[adamldoyle]

Description

httpApi authorizer's have their config in the provider section with a name that can be used by httpApi events to attach that authorizer. The authorizer's underlying function is separately defined and is allowed to have a different name than the authorizer config in the provider section. The current implementation by serverless-offline requires that both of those names are the same. This PR fixes this issue by embedding all of the provider config and setting the function name to the one defined in the config.

Motivation and Context

Fixes #1624

How Has This Been Tested?

Manually tested with a small sample app that reproduced the initial issue. Updated existing integration tests that weren't actually using the correct authorizer names (they were using the function names). Added new integration test to reference an authorizer based on config name and have it point to a function name with a different name.

Screenshots (if appropriate):

N/A