Isisminer has been refactored to be callable and Makefile tests converted to gtest format (#5579)

* Fixed minor misspellings in error messages. Addresses #5516.

* Test data added for isisminer. Addresses #5516.

* Converted isisminer Makefile tests to gtest format. Addresses #5516.

* Converted isisminer application to callable function. Addresses #5516.

* Minor tweak to isisminer csvwriter test. Addresses #5516.

* Added compareCsvLineCustomDelimiter method, specifically for isisminer testing support. Addresses #5516.

* Removed isisminer Makefile tests (replaced by gtests) and updated CHANGELOG reflecting conversion of isisminer to callable app. Addresses #5516.

* Replace isis cube in /isis/tests/data/isisminer/gistest with isd and label files. Minor tweaks to FunctionalTestsIsisminer.cpp. History entry added to isisminer.xml. Addresses #5516.

* Minor changes for conversion of isisminer to callable app. Addresses #5516.

* Had to add data file index.lbl to the .gitignore file for it to be uploaded. Addresses #5516.