refactor: templateFiles as dict instead of individual parameters insetTemplateFilename

[ombahiwal]

from list of issues #17

• Issue: Pass all the template files in a dictionary instead of all of them individually like here.

Changes:

• The function setTemplateFilename now takes a single templateFiles dictionary as an argument, where keys are the names of the expected filenames (like EDfilename, SEDfilename, etc.) and values are the actual filenames (e.g., 'EDtemplate', 'SEDtemplate', etc.).
• The function loops over the templateFiles dict. For each key-value pair, it processes the file similarly to how it did for individual parameters before, checking the filename extension and constructing the file path.
• By using a dict, you can easily add or remove template files without changing the function signature or adding new parameters. It's now easier to modify and extend the template setup.

[ombahiwal]

@rthedin

[rthedin]

Lots of changes made to make sure the proposed changes are in line with what was already in the code. Unfortunately with the refactor, several checks and details were deleted and had to be restored. Additional checks on the input dictionary has been put in place too.

[rthedin]

This is good to go. Thanks for the contribution, @ombahiwal.