[Feature Request] Add substring check for `IfElse` plugins

[kamakazikamikaze]

The plugins will perform full-string comparison actions. However there are times when performing a substring check is beneficial.

This issue requests that a substring option be added to the logic of the compareString method:

rundeck-conditional-logic-plugin/src/main/java/com/bioraft/rundeck/conditional/IfElse.java

Lines 138 to 155 in c403a96

	private String compareString(String operator, String testValue, String comparisonValue) {
	if (operator.equals(STRING_BEG) && testValue.startsWith(comparisonValue)) {
	return STRING_BEG;
	} else if (operator.equals(STRING_END) && testValue.endsWith(comparisonValue)) {
	return STRING_END;
	}
	int compare = testValue.compareTo(comparisonValue);
	if (operator.equals(STRING_LT) && compare < 0) {
	return STRING_LT;
	} else if (operator.equals(STRING_LE) && compare <= 0) {
	return STRING_LE;
	} else if (operator.equals(STRING_GE) && compare >= 0) {
	return STRING_GE;
	} else if (operator.equals(STRING_GT) && compare > 0) {
	return STRING_GT;
	}
	return "";

Logic could be added to check if operator.equals(STRING_SUB), and if so, enter a different block than lines 145-154, where testValue.contains(comparisonValue) is executed and the result checked for the appropriate return value.