[466607] Enhance EMFModelProvider to consider multiple resources at once

The EMFModelProvider now overrides the getMappings(Resource[] ...)
method to allow for optimized results.

Depending on the EMF Compare resolution settings the logical model can
not be computed as a whole when only looking at single resources. The
getMappings(Resource[] ...) method now uses the already available
multi-resource input to combine overlapping logical models to a single
model.

Since the EMFModelProvider is for example used during merging, the
optimized results avoid redundant comparisons and mergings and therefore
save time and computation power.

Includes testcases.

Bug: 466607
Signed-off-by: Stefan Dirix <sdirix@eclipsesource.com>
Change-Id: Id928bc1a05e353bf2b721243c264d09de07eebc3
13 files changed