tests: fix test 558, 1330 for MSVC, allow TrackMemory with MSVC in cmake

Extend output filter to pick up backslashes. This makes them pass in CI
when run in the vcpkg MSVC job, for example.

Also:
- cmake: allow TrackMemory, aka `ENABLE_CURLDEBUG` again. Drop FIXME.
- cmake: drop stale TODO.
- runtests: include the word 'TrackMemory' in the message disabling it.

Follow-up to 9f23c8f201 #14541
Follow-up to 94c596bbc5 #16283

Closes #16289

tests/data/test1330

@@ -39,7 +39,7 @@ MEM unit%TESTNUMBER.c: free()
 s/ =.*//
 s/\(.*\)/()/
 s/:\d+/:/
-s:^(MEM )(.*/)(.*):$1$3:
+s:^(MEM )(.*[/\\])(.*):$1$3:
 s/\r\n/\n/
 s/^MEM getenv.c: realloc\(\)[\n]$//
 s/^MEM getenv.c: free\(\)[\n]$//

tests/data/test558

@@ -49,7 +49,7 @@ s/^MEM escape.c:\d+ free\(\(nil\)\)[\n]$//
 s/ =.*//
 s/\(.*\)/()/
 s/:\d+/:/
-s:^(MEM |FD )(.*/)(.*):$1$3:
+s:^(MEM |FD )(.*[/\\])(.*):$1$3:
 s/\r\n/\n/
 s/^MEM getenv.c: realloc\(\)[\n]$//
 s/^MEM getenv.c: free\(\)[\n]$//