Add Modular Exponentiation operation

[p-leriche]

Adds a BigInt-based modular exponentiation operation to Arithmetic/Logic, supporting decimal and hex inputs, flexible input handling, and clear error reporting.

Resolves #2411

Dependencies:
Now depends on #2205 (following 8b7818a)

[CLAassistant]

All committers have signed the CLA.

[p-leriche]

(Cleaned out additional commits for extra functions ExtendedGCD and ModularInverse under development, shortly to be the subject of additional PRs.)

[lzandman]

Why did you already add these Exponentiation, Inverse and GCD operations to the Categories.json in #2205? I'm seeing <operation> could not be found warnings in the browser console. Wouldn't it have been more logical to add the relevant lines to these individual PRs?

[p-leriche]

@lzandman - Just hang in there 😀. Maintainers have merged #2205 hopefully with the expectation of merging the new functions shortly. I'm committed to promptly addressing any comments they raise in order to expedite the completion of this little project of mine.

[lzandman]

@lzandman - Just hang in there 😀. Maintainers have merged #2205 hopefully with the expectation of merging the new functions shortly.

Yes, I get that. I was just trying to say that it would've been more clean to have your individual operations PRs add their own specific operation entry to categories.json and not touch categories.json in #2205 at all.

[p-leriche]

01May26: Rebased on current upstream master.