First step to implementing classically-controlled gates

[theRoughCode]

This PR is meant to serve as guidance to how to implement classically-controlled operations within the execution path visualization feature described in #158.

Here are some notes:

1. The JS visualizer already handles classically-controlled gates and their interactivity.
2. This PR depends on this PR to be merged to be able to distinguish classically-controlled operations.

In this PR, we:

1. Use the IsConditional flag in the RuntimeMetadata class to check if the given operation is a classically-controlled operation.
2. Override the logic for ApplyIfElseR with a custom TracerApplyIfElse.

If this logic makes sense, the next steps are to:

• Override conditional logic for all other variants of ApplyIfElse
• Perform an IRewriteStep to convert if/else statements to ApplyIfElse
• Reduce ApplyIfOne and ApplyIfZero to ApplyIfElse.