tests: replace remaining CR bytes with the new macro %CR

There is no more mixed-newline file in the repository after this patch.
Except for`.bat` and `.sln` files (4 in total), all files use LF
newlines.

Also:
- `spacecheck.pl`: drop mixed-EOL exception for test data.
- runtests: add option `-w` to check if test data has stray CR bytes in
  them.
- build: enable the option above in test targets, except the CI-specific
  one where `spacecheck.pl` does this job already.
- tested OK (with expected failures) in CI with stray CRs added.
- cmake: enable option `-a` for the `tests` target. To continue testing
  after a failed test.

Follow-up to 63e9721b63 #19313
Follow-up to 6cf3d7b1b1 #19318
Follow-up to 4d2a05d3fe #19284

Closes #19347

tests/data/test341

@@ -9,13 +9,13 @@ HTTP GET
 # Server-side
 <reply>
 <data nocheck="yes">
-HTTP/1.1 200 funky chunky!
-Server: fakeit/0.9 fakeitbad/1.0
-Transfer-Encoding: chunked
-Trailer: chunky-trailer
-Connection: mooo
-ETag: "asdf"
-
+HTTP/1.1 200 funky chunky!%CR
+Server: fakeit/0.9 fakeitbad/1.0%CR
+Transfer-Encoding: chunked%CR
+Trailer: chunky-trailer%CR
+Connection: mooo%CR
+ETag: "asdf"%CR
+%CR
 40
 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 30