LPS-44908 Remove getContentValue() method from TypedSettings because it cannot be used as it is defined and also because it does not work at runtime (as ContentUtil class may not be seen depending on which ClassLoader we are living on).
LPS-44908 Define getter methods without default value parameter to be able to gradually clean the hard coded default values (the idea is to move the default values to portal.properties and use the methods without default values for already migrated properties).
LPS-44908 Interpret properties which contain the empty string as non-existent when reading them from portal.properties
LPS-44908 EMTPY_STRING_ARRAY was spelled wrong, EMTPY instead of EMPTY, but in any case, we can use StringPool