Different loggers had different logic to handle unnamed wasm functions.
This CL makes sure that we always set a reasonable name when logging
wasm code, and removes handling for unnamed code in individual loggers.

Since logging only happens on user action, the code is not optimized for
performance (i.e. we always just write to a {std::string}, even if the
length of the string is known to be limited).

R=jkummerow@chromium.org

Bug: chromium:863205
Change-Id: I941f7e8050c97dc938afd7883aaeb3b6347b762d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2064977Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66370}