IDLE: add a bytecode browser

Feature or enhancement

Completing the browser series alongside the token (#152941) and AST (#152942) browsers, seeing the disassembled bytecode helps in learning how CPython compiles code and in understanding what the interpreter actually executes.

I propose a Disassembly Browser added as an extension on the Tools menu (Shell and editor). It shows the disassembled bytecode of the current window. Each code object is a collapsible row of its instructions; nested code objects (functions, classes, comprehensions, ...) are shown as further rows.

Interaction:

• Selecting an instruction highlights the corresponding source in the editor and, while the browser has focus, moves the cursor there.
• The browser follows the editor: selecting text or moving the cursor selects the matching instructions.
• Double-clicking a row (or pressing Escape) hides the browser, revealing the editor at that instruction.
• Scope is the editor selection if there is one, else the Shell's current input, else the whole window.

While the debugger is stopped, the browser follows it instead of the editor: it shows the code object that is actually executing and marks the instruction the frame is stopped at.

It shares the window skeleton and editor-sync mechanism with the token and AST browsers.

A PR will follow.

Linked PRs

• gh-152974

Review the token and AST browsers, their shared window skeleton and editor-sync mechanism, and linked PR gh-152974 first. Use the issue's interaction and scope rules as the acceptance criteria: bytecode should be browsable by code object, synchronize with the editor or debugger, and hide back to the relevant instruction.