[projmgr] Fix optional empty layer report

Author: spcaipers-arm

tools/projmgr/src/ProjMgrWorker.cpp

@@ -895,6 +895,10 @@ bool ProjMgrWorker::ProcessLayerCombinations(ContextItem& context, LayersDiscove
         }
       }
 
+      // init list of compatible layers with all required layer types
+      for (const auto& type : discover.requiredLayerTypes) {
+        context.compatibleLayers.insert({ type, StrVec() });
+      }
       // update list of compatible layers
       context.validConnections.push_back(combination);
       for (const auto& [type, _] : discover.candidateClayers) {

tools/projmgr/test/data/TestLayers/ref/no_compiler.cbuild-idx.yml

@@ -10,11 +10,13 @@ build-idx:
             - Board-Layer: $SolutionDir()$/select.clayer.yml
               settings:
                 - set: set1.select1 (provided connections A and B - set 1 select 1)
+            - Select1-Layer: ""
         - configuration: 
           variables:
             - Board-Layer: $SolutionDir()$/select.clayer.yml
               settings:
                 - set: set1.select2 (provided connections B and C - set 1 select 2)
+            - Select1-Layer: ""
   select-compiler:
     - compiler: AC6
     - compiler: GCC

tools/projmgr/test/data/TestLayers/ref/select.cbuild-idx.yml

@@ -10,11 +10,13 @@ build-idx:
             - Board-Layer: $SolutionDir()$/select.clayer.yml
               settings:
                 - set: set1.select1 (provided connections A and B - set 1 select 1)
+            - Select1-Layer: ""
         - configuration: 
           variables:
             - Board-Layer: $SolutionDir()$/select.clayer.yml
               settings:
                 - set: set1.select2 (provided connections B and C - set 1 select 2)
+            - Select1-Layer: ""
   cprojects:
     - cproject: select.cproject.yml
       clayers:

tools/projmgr/test/data/TestLayers/searchpath.cproject.yml

@@ -3,3 +3,4 @@
 project:
   layers:
     - type: TestVariant
+      optional: false

tools/projmgr/test/data/TestLayers/variables-notdefined.cproject.yml

@@ -4,3 +4,4 @@ project:
   layers:
     - layer: $NotDefined$
       type: Board
+      optional: false