cmake: fix clang-tidy builds to verify tests, fix fallouts

- cmake: disable test bundles for clang-tidy builds.
  clang-tidy ignores #included .c sources, and incompatible with unity
  and bundles. It caused clang-tidy ignoring all test sources. It also
  means this is the first time tests sources are checked with
  clang-tidy. (autotools doesn't run it on tests.)

- cmake: update description for `CURL_TEST_BUNDLES` option.

- fix tests using special `CURLE_*` enums that were missing from
  `curl/curl.h`. Add them as reserved codes.

- fix about ~50 other issues detected by clang-tidy: unchecked results,
  NULL derefs, memory leaks, casts to enums, unused assigments,
  uninitialized `errno` uses, unchecked `open`, indent, and more.

- drop unnecessary casts (lib1533, lib3207).

- suppress a few impossible cases with detailed `NOLINT`s.

- lib/escape.c: drop `NOLINT` no longer necessary.
  Follow-up to 72abf7c13a #13862 (possibly)

- extend two existing `NOLINT` comments with details.

Follow-up to fabfa8e402 #15825

Closes #16756

tests/unit/unit1654.c

@@ -88,7 +88,7 @@ UNITTEST_START
   result = Curl_altsvc_parse(curl, asi,
                              "h2=\"example.net:443\"; ma=\"180\";\r\n",
                              ALPN_h2, "example.net", 80);
-  fail_if(result, "Curl_altsvc_parse(4) failed!");
+  fail_if(result, "Curl_altsvc_parse(5) failed!");
   fail_unless(Curl_llist_count(&asi->list) == 10, "wrong number of entries");
 
   result =
@@ -96,34 +96,38 @@ UNITTEST_START
                       "h2=\":443\", h3=\":443\"; "
                       "persist = \"1\"; ma = 120;\r\n",
                       ALPN_h1, "curl.se", 80);
-  fail_if(result, "Curl_altsvc_parse(5) failed!");
+  fail_if(result, "Curl_altsvc_parse(6) failed!");
   fail_unless(Curl_llist_count(&asi->list) == 12, "wrong number of entries");
 
   /* clear that one again and decrease the counter */
   result = Curl_altsvc_parse(curl, asi, "clear;\r\n",
                              ALPN_h1, "curl.se", 80);
-  fail_if(result, "Curl_altsvc_parse(6) failed!");
+  fail_if(result, "Curl_altsvc_parse(7) failed!");
   fail_unless(Curl_llist_count(&asi->list) == 10, "wrong number of entries");
 
   /* only a non-existing alpn */
   result = Curl_altsvc_parse(curl, asi,
                              "h6=\"example.net:443\"; ma=\"180\";\r\n",
                              ALPN_h2, "5.example.net", 80);
+  fail_if(result, "Curl_altsvc_parse(8) failed!");
 
   /* missing quote in alpn host */
   result = Curl_altsvc_parse(curl, asi,
                              "h2=\"example.net:443,; ma=\"180\";\r\n",
                              ALPN_h2, "6.example.net", 80);
+  fail_if(result, "Curl_altsvc_parse(9) failed!");
 
   /* missing port in host name */
   result = Curl_altsvc_parse(curl, asi,
                              "h2=\"example.net\"; ma=\"180\";\r\n",
                              ALPN_h2, "7.example.net", 80);
+  fail_if(result, "Curl_altsvc_parse(10) failed!");
 
   /* illegal port in host name */
   result = Curl_altsvc_parse(curl, asi,
                              "h2=\"example.net:70000\"; ma=\"180\";\r\n",
                              ALPN_h2, "8.example.net", 80);
+  fail_if(result, "Curl_altsvc_parse(11) failed!");
 
   Curl_altsvc_save(curl, asi, outname);