Improve marbl_config_and_parms_type for better search

[mnlevy1981]

As of 6ba527f (on the enhancements/initialization branch of my fork of MARBL), I added the ability for the GCM to call

call marbl_instance%parameters%put([varname], [value], marbl_instance%StatusLog)

For each put() call, though, MARBL will do a linear search through marbl_instance%parameters%vars(:) and look for the index that corresponds to [varname], which is O(N). Restructuring marbl_config_and_parms_type would allow us to speed this up significantly; @klindsay28 has mentioned using a binary tree or a hash as two possibilities.

I believe this can be done without affecting the MARBL interface at all, so I don't think it is necessary for MARBL 1.0.0... but I do want to keep it in mind.

[mnlevy1981]

I think it should be noted somewhere -- without running CISO, MARBL has 157 variables that can be set during config and 416 that can be set during init. Turning CISO on increases those to 170 and 546, respectively.