LoadMemoryAnnotation uses deprecated ComponentName

[chick]

Type of issue: Code cleanup, release issue

Description:
The LoadMemoryAnnotation uses a ComponentName annotation to
describe the Memory to be loaded. We should eliminate deprecations like this

What is the expected behavior?

The code is clean without these warnings. If we do not fix or fail to mark the
LoadMemoryAnnotation as also deprecated we limit our ability to follow
through on removing the deprecated code on the next API changing release

Strategy:
I think the answer here is that we need to deprecate LoadMemoryAnnotation and create a new parallel one that uses ReferenceTarget or other modern for of firrtl locator