Fix compiler bug with nested optional arguments

This commit fixes compiler bug where it fails when optional values are
compiled into absent values in nested calls.

- Throw exception with more context for easier future debugging.
- Add better validation of argument values for nested calls.
- Refactor `FunctionCallCompiler` for better clarity and modularize it
  to make it more maintainable and testable.
- Refactor related interface to not have `I` prefix, and
  function/variable names for better clarity.

Context:

Discovered this issue while attempting to call
`RunInlineCodeAsTrustedInstaller` which in turn invokes `RunPowerShell`
for issue #246. This led to the realization that despite parameters
flagged as optional, the nested argument compilation didn't support
them.

tests/unit/shared/Assertions/ExpectDeepThrowsError.ts

@@ -1,7 +1,7 @@
 import { expect } from 'vitest';
 
 // `toThrowError` does not assert the error type (https://github.com/vitest-dev/vitest/blob/v0.34.2/docs/api/expect.md#tothrowerror)
-export function expectThrowsError<T extends Error>(delegate: () => void, expected: T) {
+export function expectDeepThrowsError<T extends Error>(delegate: () => void, expected: T) {
   // arrange
   if (!expected) {
     throw new Error('missing expected');