Updates marci2isis to add variable exposure times and associated frame sequences (#3501)

* Update date and other metadata

* ckwriter_test_fix

* Fix unintentional cmakelists change

* Updated voy2isis to add instrument parameter which can be used to specify the instrument name wac or nac if it is not provided in the image label

* Added simple test

* Updates test and documentation for voy2isis adds instrument_name update

* Updated history documentation to add ticket number for voy2isis changes

* Updated to reverse frameseq number appropriately with flip

* Remove commented-out code

* Added documentation for change and test

* Updated no exposure duration in varexp file condition

* Re-remove iTime.h

* Update warning message for assuming a single exposure time