Update tests to add error counts

When validating, the output has a summary of error/warning counts, so
update tests appropriately.

test/falco_tests.yaml

@@ -262,6 +262,7 @@ trace_files: !mux
   invalid_not_yaml:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rules content is not yaml
       ---
       This is not yaml
@@ -273,6 +274,7 @@ trace_files: !mux
   invalid_not_array:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rules content is not yaml array of objects
       ---
       foo: bar
@@ -284,6 +286,7 @@ trace_files: !mux
   invalid_array_item_not_object:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Unexpected element of type string. Each element should be a yaml associative array.
       ---
       - foo
@@ -295,6 +298,7 @@ trace_files: !mux
   invalid_unexpected object:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Unknown rule object: {foo="bar"}
       ---
       - foo: bar
@@ -306,6 +310,7 @@ trace_files: !mux
   invalid_engine_version_not_number:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Value of required_engine_version must be a number
       ---
       - required_engine_version: not-a-number
@@ -317,6 +322,7 @@ trace_files: !mux
   invalid_yaml_parse_error:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       mapping values are not allowed in this context
       ---
       this : is : not : yaml
@@ -328,6 +334,7 @@ trace_files: !mux
   invalid_list_without_items:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       List must have property items
       ---
       - list: bad_list
@@ -340,6 +347,7 @@ trace_files: !mux
   invalid_macro_without_condition:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Macro must have property condition
       ---
       - macro: bad_macro
@@ -352,6 +360,7 @@ trace_files: !mux
   invalid_rule_without_output:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rule must have property output
       ---
       - rule: no output rule
@@ -366,6 +375,7 @@ trace_files: !mux
   invalid_append_rule_without_condition:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rule must have property condition
       ---
       - rule: no condition rule
@@ -378,6 +388,7 @@ trace_files: !mux
   invalid_append_macro_dangling:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Macro dangling append has 'append' key but no macro by that name already exists
       ---
       - macro: dangling append
@@ -391,6 +402,7 @@ trace_files: !mux
   invalid_list_append_dangling:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       List my_list has 'append' key but no list by that name already exists
       ---
       - list: my_list
@@ -404,6 +416,7 @@ trace_files: !mux
   invalid_rule_append_dangling:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rule my_rule has 'append' key but no rule by that name already exists
       ---
       - rule: my_rule
@@ -450,6 +463,7 @@ trace_files: !mux
   invalid_overwrite_macro_multiple_docs:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Compilation error when compiling "foo": Undefined macro 'foo' used in filter.
       ---
       - macro: some macro
@@ -463,6 +477,7 @@ trace_files: !mux
   invalid_append_macro_multiple_docs:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Compilation error when compiling "evt.type=execve foo": 17: syntax error, unexpected 'foo', expecting 'or', 'and'
       ---
       - macro: some macro
@@ -521,6 +536,7 @@ trace_files: !mux
   invalid_overwrite_rule_multiple_docs:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Undefined macro 'bar' used in filter.
       ---
       - rule: some rule
@@ -559,6 +575,7 @@ trace_files: !mux
   invalid_missing_rule_name:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Rule name is empty
       ---
       - rule:
@@ -573,6 +590,7 @@ trace_files: !mux
   invalid_missing_list_name:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       List name is empty
       ---
       - list:
@@ -585,6 +603,7 @@ trace_files: !mux
   invalid_missing_macro_name:
     exit_status: 1
     stdout_is: |+
+      1 errors:
       Macro name is empty
       ---
       - macro: