tests: always make bundles, adapt build and tests

Make test bundles the default. Drop non-bundle build mode.
Also do all the optimizations and tidy-ups this allows, simpler builds,
less bundle exceptions, streamlined build mechanics.

Also rework the init/deinit macro magic for unit tests. The new method
allows using unique init/deinit function names, and calling them with
arguments. This is in turn makes it possible to reduce the use of global
variables.

Note this drop existing build options `-DCURL_TEST_BUNDLES=` from cmake
and `--enable-test-bundles` / `--disable-test-bundles` from autotools.

Also:
- rename test entry functions to have unique names: `test_<testname>`
  This removes the last exception that was handled in the generator.
- fix `make dist` to not miss test sources with test bundles enabled.
- sync and merge `tests/mk-bundle.pl` into `scripts/mk-unity.pl`.
- mk-unity.pl: add `--embed` option and use it when `CURL_CLANG_TIDY=ON`
  to ensure that `clang-tidy` does not miss external test C sources.
  (because `clang-tidy` ignores code that's #included.)
- tests/unit: drop no-op setup/stop functions.
- tests: reduce symbol scopes, global macros, other fixes and tidy-ups.
- tool1621: fix to run, also fix it to pass.
- sockfilt: fix Windows compiler warning in certain unity include order,
  by explicitly including `warnless.h`.

Follow-up to 6897aeb105 #17468

Closes #17590

tests/unit/unit1614.c

@@ -25,34 +25,20 @@
 
 #include "noproxy.h"
 
-static CURLcode unit_setup(void)
+static CURLcode test_unit1614(char *arg)
 {
-  return CURLE_OK;
-}
+  UNITTEST_BEGIN_SIMPLE
 
-static void unit_stop(void)
-{
-
-}
-
-struct check {
-  const char *a;
-  const char *n;
-  unsigned int bits;
-  bool match;
-};
-
-struct noproxy {
-  const char *a;
-  const char *n;
-  bool match;
-};
-
-UNITTEST_START
 #if defined(DEBUGBUILD) && !defined(CURL_DISABLE_PROXY)
-{
   int i;
   int err = 0;
+
+  struct check {
+  const char *a;
+    const char *n;
+    unsigned int bits;
+    bool match;
+  };
   struct check list4[]= {
     { "192.160.0.1", "192.160.0.1", 33, FALSE},
     { "192.160.0.1", "192.160.0.1", 32, TRUE},
@@ -78,6 +64,11 @@ UNITTEST_START
     { NULL, NULL, 0, FALSE} /* end marker */
   };
 #endif
+  struct noproxy {
+    const char *a;
+    const char *n;
+    bool match;
+  };
   struct noproxy list[]= {
     { "www.example.com", "localhost .example.com .example.de", FALSE},
     { "www.example.com", "localhost,.example.com,.example.de", TRUE},
@@ -161,6 +152,7 @@ UNITTEST_START
     }
   }
   fail_if(err, "errors");
-}
 #endif
-UNITTEST_STOP
+
+  UNITTEST_END_SIMPLE
+}