Previously we had the debugger / inspector support declared in
debug-interface.h, but the implementation was sprinkled all across
api.cc, which was quite messy. This moves the relevant macros and
other bits into api-macros.h (with api-macros-undef.h to support
jumbo builds), and moves the debugger interface implementation to
src/debug/debug-interface.cc.

Bug: chromium:1162229
Change-Id: I6965ebf2301459c89e3217bd87396ec353d814e9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2653154
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72392}