tests: avoid hard-coded CRLFs in more sections

- `reply/data*`, `verify/stdout`, `verify/stderr`, `verify/file*`,
  `verify/proxy`:
  - make `crlf="yes"` force CRLF to all lines, instead of just applying
    to HTTP protocol headers.
  - add support for `crlf="headers"` that only converts HTTP protocol
    header lines to CRLF. (previously done via `crlf="yes"`.)
  - use `crlf="headers"` where possible.

- `reply/connect*`:
  - add support for `crlf="yes"` and `crlf="headers"`.
  - use them where possible.

- `client/file*`, `client/stdin`:
  - add support for `crlf="yes"`.
  - use it where possible.

- `reply/data*`, `verify/protocol`:
  - replace existing uses of `crlf="yes"` with `crlf="headers`" where it
    does not change the result.

Reducing the number of `tests/data/test*`:
- CRLF newlines from 10295 to 1985. (119985 lines total)
- files with mixed newlines from 656 to 113. (1890 files total)

After this patch there remain 141 sections with mixed newlines, where
the mixing is not split between headers/non-headers. There is no obvious
pattern here. Some of the CRLF uses might be accidental, or
non-significant. They will be tackled in a future patch.

Follow-up to 6cf3d7b1b1 #19318
Follow-up to 4d2a05d3fe #19284

Closes #19313

tests/data/test3003

@@ -19,11 +19,11 @@ smtp
 <name>
 SMTP multiple and invalid (last) --mail-rcpt and --mail-rcpt-allowfails
 </name>
-<stdin>
-From: different
-To: another
-
-body
+<stdin crlf="yes">
+From: different
+To: another
+
+body
 </stdin>
 <command>
 smtp://%HOSTIP:%SMTPPORT/%TESTNUMBER --mail-rcpt-allowfails --mail-rcpt recipient.one@example.com --mail-rcpt recipient.two@example.com --mail-rcpt recipient.three@example.com --mail-rcpt recipient.four@example.com --mail-rcpt invalid.five --mail-from sender@example.com -T -