Improved domain and type query support for registerCommand

[jeremiah-corrado]

Made the following improvements to registerCommand:

• array formals with static element types aren't instantiated for all dtypes
• array formal types can reference domain and type queries from other formal types
  • allows two array arguments to always have the same rank or type (preventing separate instantiation for both formals)

Examples:

The following proc is only instantiated for supported array ranks (e.g., "asdf<1>", "asdf<2>", ...) because the element type is static:

@arkouda.registerCommand()
proc asdf(ref x1: [?d] real) throws {
    ...
}

The following proc is only instantiated for one set of dtype and rank arguments (e.g., "pqrs<int,1>", "pqrs<real,1>", ...) because the domain and element type are shared:

@arkouda.registerCommand()
proc pqrs(ref x1: [?d] ?t, x2: [d] t) throws {
    ...
}

[ajpotts]

This is awesome! Thanks!

[stress-tess]

looks great!! thanks jeremiah!