Added overdue support in Parser
General logging for all Command
Added javadoc and naming conventions
Allowed user to search overdue task

Updated test cases as well
Added more logging messages to classes
Fix schedule date comparison and conflict issue
Merge branch 'logging_refactor'
Refactored and Fixed ViewCommand
Refactored SearchCommand
Updated ViewCommand for flexibility
Fix test cases due to change in format

However correctness is not checked.
Refactored all formatting into Formatter
Remove redundant variables.