refactor!: organize algorithms in subdirectories

[c-dilks]

The number of files per algorithms has been growing, so the algorithms are now organized into individual subdirectories, with the following files:

File(s)	Description
Algorithm.{h,cc}	the algorithm implementation
Validator.{h,cc}	algorithm validator
Config.yaml	algorithm configuration
Bindings.cc	C bindings (for Fortran)

• This change also allows algorithms to include more classes and headers, if needed.
• This is a breaking change for consumers which include algorithm headers. For example:

#include <iguana/algorithms/clas12/MomentumCorrection.h>             # before the change
#include <iguana/algorithms/clas12/MomentumCorrection/Algorithm.h>   # after the change

Additional changes

• The iguana-example-* executables also have been renamed, to exclude the numbers
• Starter algorithm script make_template.sh has been renamed to make_starter.sh

[dglazier]

When is the expected merge for this branch? I would like to add the iguana stuff to the clas12root release, but would prefer to wait for this refactorisation if it is going to be soon.

[c-dilks]

When is the expected merge for this branch?

Early next week, unless we run into any difficult issues here.

[c-dilks]

@dglazier CI checks pass now. I will review the changes on Monday; I also requested your review, in case you'd like to take a second look or have any feedback.

[dglazier]

Hi Chris,
It works fine for me. The only slight issue is you end up with long include paths e.g.

  #include <iguana/algorithms/clas12/ZVertexFilter/Algorithm.h>

Cheers
Derek