fix(common): calculate already-build dependency targets correctly

When using module:target style dependencies, Builder would not track the
individual targets within the module, causing only the first target to
be built; subsequent dependency targets within that module would be
treated as already built.

This change means that builder will track individual targets within
the dependency. However, it is possible for targets to be built multiple
times if there a dependency listed for the entire module as well as for
the individual target within dependency, as in the following example,
where building project1 and project2 in one command would cause
module:mytarget to be built twice.

    builder_describe project1 \
      @/module

    builder_describe project2 \
      @/module:mytarget

This scenario should not break builds as they any configure+build
actions should be idempotent, but it could cause builds to be a little
slower, so should be corrected if identified. I do not currently plan to
further modify the dependency calculations to cater for this scenario.

Finally, if :mytarget is a child build, it is better to reference the
child module directly than the parent's target, for example:

    builder_describe projec1 \
       @/module/mytarget

resources/builder.inc.sh

@@ -1682,26 +1682,26 @@ _builder_do_build_deps() {
       continue
     fi
 
-    # Only configure and build the dependency once per invocation
-    if builder_has_module_been_built "$dep"; then
-      continue
-    fi
-
     dep_target=
     if [[ ! -z ${_builder_dep_targets[$dep]+x} ]]; then
       # TODO: in the future split _builder_dep_targets into comma-separated
       #       array for multiple targets for a dep?
       dep_target=${_builder_dep_targets[$dep]}
     fi
 
-    builder_set_module_has_been_built "$dep"
+    # Only configure and build the dependency once per invocation
+    if builder_has_module_been_built "$dep$dep_target"; then
+      continue
+    fi
+
+    builder_set_module_has_been_built "$dep$dep_target"
     "$REPO_ROOT/$dep/build.sh" "configure$dep_target" "build$dep_target" \
       $builder_verbose \
       $builder_debug \
       $_builder_build_deps \
       --builder-dep-parent "$THIS_SCRIPT_IDENTIFIER" && (
       if $_builder_debug_internal; then
-        builder_echo success "## Dependency $dep for $_builder_matched_action_name successfully"
+        builder_echo success "## Dependency $dep$dep_target for $_builder_matched_action_name successfully"
       fi
     ) || (
       result=$?