Fix FSHRunner command execution

[dotasek]

Command execution should use CommandLine to construct arguments rather than concatenating Strings

[dotasek]

In addition to the added unit tests, this refactor was also tested locally on Mac and on Windows by running against the https://github.com/HL7/fhir-sdoh-clinicalcare IG.

The following CLI params were used in order to emulate conditions similar to both the auto-ig-builder and local developer execution:

java -jar org.hl7.fhir.publisher.cli-1.3.20-refactor.jar -ig /IGS/fhir-sdoh-clinicalcare > ig-build.refactor.log

java -jar org.hl7.fhir.publisher.cli-1.3.20-refactor.jar -ig /IGS/fhir-sdoh-clinicalcare-w-fsh-ini > ig-build-w-fsh-ini.refactor.log

java -jar org.hl7.fhir.publisher.cli-1.3.20-refactor.jar -auto-ig-build -ig /IGS/fhir-sdoh-clinicalcare > ig-build-auto-ig-build.refactor.log

java -jar org.hl7.fhir.publisher.cli-1.3.20-refactor.jar -auto-ig-build -ig /IGS/fhir-sdoh-clinicalcare-w-fsh-ini > ig-build-auto-ig-build-w-fsh-ini.refactor.log

The fhir-sdoh-clinicalcare-w-fsh-ini directory was an exact copy of the original IG with the following fhs.ini file added:

[FSH]
sushi-version=3.0.0

All runs excuted as expected with the correct --require-latest param visible for -auto-ig-build runs, and the following output consistently produced:

Sushi: ========================= SUSHI RESULTS ===========================       (02:00.332)
Sushi: |  -------------------------------------------------------------  |       (02:00.332)
Sushi: | |    Profiles   |  Extensions  |   Logicals   |   Resources   | |       (02:00.332)
Sushi: | |-------------------------------------------------------------| |       (02:00.332)
Sushi: | |      19       |      2       |      0       |       0       | |       (02:00.332)
Sushi: |  -------------------------------------------------------------  |       (02:00.333)
Sushi: |  -------------------------------------------------------------  |       (02:00.333)
Sushi: | |      ValueSets     |    CodeSystems    |     Instances      | |       (02:00.333)
Sushi: | |-------------------------------------------------------------| |       (02:00.333)
Sushi: | |         14         |         1         |         67         | |       (02:00.333)
Sushi: |  -------------------------------------------------------------  |       (02:00.333)
Sushi: |                                                                 |       (02:00.333)
Sushi: ===================================================================       (02:00.333)
Sushi: | You should mullet over.                0 Errors      5 Warnings |       (02:00.333)
Sushi: ===================================================================       (02:00.333)
Sushi: