Clarify dependency violation message

I was bothered by a couple of things in the dependency violation message
and this change fixes them.

1. "Are we missing an abstraction?" is not helpful context.
2. "Is the code making the reference, and the referenced constant, in
   the right packages?" was not grammatically correct or clear.

TROUBLESHOOT.md

@@ -28,8 +28,7 @@ See: [USAGE.md - Enforcing dependency boundary](USAGE.md#Enforcing-dependency-bo
 
 > /Users/JaneDoe/src/github.com/sample-project/billing/app/jobs/document_processing_job.rb:48:6
 > Dependency violation: ::Edi::Source belongs to 'edi', but 'billing' does not specify a dependency on 'edi'.
-> Are we missing an abstraction?
-> Is the code making the reference, and the referenced constant, in the right packages?
+> Are the constant and its references in the right packages?
 >
 > Inference details: 'Edi::Source' refers to ::Edi::Source which seems to be defined in edi/app/models/edi/source.rb.
 

lib/packwerk/reference_checking/checkers/dependency_checker.rb

@@ -40,8 +40,7 @@ def message(reference)
 
           <<~EOS
             Dependency violation: #{const_name} belongs to '#{const_package}', but '#{ref_package}' does not specify a dependency on '#{const_package}'.
-            Are we missing an abstraction?
-            Is the code making the reference, and the referenced constant, in the right packages?
+            Are the constant and its references in the right packages?
 
             #{standard_help_message(reference)}
           EOS

test/unit/packwerk/reference_offense_test.rb

@@ -29,8 +29,7 @@ class ReferenceOffenseTest < Minitest::Test
 
       expected = <<~EXPECTED
         Dependency violation: ::SomeName belongs to 'destination_package', but 'components/source' does not specify a dependency on 'destination_package'.
-        Are we missing an abstraction?
-        Is the code making the reference, and the referenced constant, in the right packages?
+        Are the constant and its references in the right packages?
 
         Inference details: this is a reference to ::SomeName which seems to be defined in some/location.rb.
         To receive help interpreting or resolving this error message, see: https://github.com/Shopify/packwerk/blob/main/TROUBLESHOOT.md#Troubleshooting-violations