Handle all standalone combinations of LC_NOTEs w/ & w/o addr & uuid

Fill out ProcessMachCore::DoLoadCore to handle LC_NOTE hints with
a UUID or with a UUID+address, and load the binary at the specified
offset correctly.  Add tests for all four combinations.  Change
DynamicLoaderStatic to not re-set a Section's load address in the
Target if it's already been specified.

Differential Revision: https://reviews.llvm.org/D99571
rdar://51490545