Improve test coverage of SS002 rule function

Previously the test data for the unit tests of this function did not provide full coverage of all valid sketch filename
formats.

Author: per1234

internal/rule/rulefunction/sketch_test.go

@@ -75,7 +75,7 @@ func TestSketchNameMismatch(t *testing.T) {
 func TestProhibitedCharactersInSketchFileName(t *testing.T) {
 	testTables := []sketchRuleFunctionTestTable{
 		{"Has prohibited characters", "ProhibitedCharactersInFileName", ruleresult.Fail, "^Prohibited CharactersInFileName.h$"},
-		{"No prohibited characters", "Valid", ruleresult.Pass, ""},
+		{"No prohibited characters", "AllowedCharactersInFilenames", ruleresult.Pass, ""},
 	}
 
 	checkSketchRuleFunction(ProhibitedCharactersInSketchFileName, testTables, t)

internal/rule/rulefunction/testdata/sketches/AllowedCharactersInFilenames/1LeadingNumber.ino

@@ -0,0 +1,2 @@
+void setup() {}
+void loop() {}