changing how output works, adding tests for output

[K20shores]

Closes #237

• Adds 'terminal' as an output format
• Uses the date time to create a file name
• Supports all of these use cases and creates unit tests for these:

# should print results to terminal
music_box -e Analytical

# should create a filename that is similar to music_box_20241108_093604.nc in the current directory
music_box -e Analytical --output-format netcdf

# should create a filename that is similar to music_box_20241108_093604.csv in the current directory
music_box -e Analytical --output-format csv

# should create a file named out.csv in the current directory
music_box -e Analytical --output-format csv -o out.csv

# should create a named out.nc in the current directory
music_box -e Analytical --output-format netcdf -o out.nc

# should create directory results and write out.nc into that directory
music_box -e Analytical --output-format netcdf -o results/out.nc

# should create directory results and write out.csv into that directory
music_box -e Analytical --output-format csv -o results/out.csv

# should create directory results and write a file with a name similar to music_box_20241108_093604.csv
music_box -e Analytical --output-format csv -o results/

# should create directory results and write a file with a name similar to music_box_20241108_093604.nc
music_box -e Analytical --output-format netcdf -o results/