composer: refactor ComposerResources into shared library

composer@2.x-hal is a header library. Any of the shared
libraries it depends on must also be included by anyone
who includes composer@2.x-hal. This means when we add a new
version of mapper, anyone who uses composer@2.x-hal must
also include the new version of the mapper. Vendors
that depend on composer@2.x-hal are broken every time we
add a new mapper.

This patch refactors ComposerResources into a seperate
shared library. ComposerResources contains all of the
mapper code. composer@2.x-hal will depend on the new
composer@2.x-resource hal. Everyone downstream must
also add the composer@2.x-resource file now. However,
they will not be broken again when we add a new mapper
version.

Bug: 136016160
Test: Compiles and boots

Change-Id: I208a954a941ed65938074cd3efb8a6893a2bc1eb