change the input of format in Parser

-change the userCommand to be an input in format to align with Logic and
UI
complete method pasrseLocation in Parser

-complete method parseLocation in Parser
change the field frequency in Task

-change the field frequency in Task to accommodate both frequency and
frequencyType
-Update Parser to minimise the need for conversion from array to String
then back
complete method parseFrequency in Parser

-complete method parseFrequency in Parser
-add method determineFrequencyType
-update FrequencyType