sigv4: URL encode the user name in the header

- split into sub functions
- add 'aws-sigv4' as keyword for many tests

Verify with test 3222

Reported-by: Trail of Bits
Closes #21923

tests/data/test3222

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="US-ASCII"?>
+<testcase>
+<info>
+<keywords>
+HTTP
+aws-sigv4
+</keywords>
+</info>
+
+# Server-side
+<reply>
+<data crlf="headers">
+HTTP/1.1 200 OK
+Date: Tue, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+Connection: close
+Content-Type: text/html
+Funny-head: yesyes
+
+-foo-
+</data>
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+<features>
+Debug
+aws
+</features>
+<name>
+aws-sigv4 with CRLF in username
+</name>
+<command>
+"http://user%0d%0a:secret@fake.fake.fake:8000/" --aws-sigv4 "aws:amz:us-east-2:es" --connect-to fake.fake.fake:8000:%HOSTIP:%HTTPPORT
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol crlf="headers">
+GET / HTTP/1.1
+Host: fake.fake.fake:8000
+Authorization: AWS4-HMAC-SHA256 Credential=user%0D%0A/19700101/us-east-2/es/aws4_request, SignedHeaders=host;x-amz-date, Signature=e5747e9555c0e96f1067cc4bf9f6055e72a185178e5dd0c2909279ec1d66360b
+X-Amz-Date: 19700101T000000Z
+User-Agent: curl/%VERSION
+Accept: */*
+
+</protocol>
+</verify>
+</testcase>