Additional adjustments to the Fleet Management sample app

[IMinchev64]

For consistency can you assign type boolean to these two variables as well

Originally posted by @MarielaTihova in #10 (comment)

These values are used in several places ("ytd", "3months", "6months", "12months") . Can you put them in an Enum or some shared object?

Originally posted by @MarielaTihova in #10 (comment)

Interface for this so that you can assign a type to it

Originally posted by @MarielaTihova in #10 (comment)

Is there any reason to use == instead of === ?

Also can you put all flying around strings in variables? If they are repeating over different files, please put them in a shared location.

Originally posted by @MarielaTihova in #10 (comment)

Please use driverDetails?.name || "" instead of "as string". This will ensure us that we have an empty string if driverDetails.name has a falsy value. Same goes for all of the fields following

Originally posted by @MarielaTihova in #10 (comment)