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/unit3211.c

@@ -27,28 +27,8 @@
 #include "uint-bset.h"
 #include "curl_trc.h"
 
-static CURLcode unit_setup(void)
-{
-  return CURLE_OK;
-}
-
-static unsigned int s1[] = {  /* spread numbers, some at slot edges */
-  0, 1, 4, 17, 63, 64, 65, 66,
-  90, 99,
-};
-static unsigned int s2[] = { /* set with all bits in slot1 set */
-  64, 65, 66, 67, 68, 69, 70, 71,
-  72, 73, 74, 75, 76, 77, 78, 79,
-  80, 81, 82, 83, 84, 85, 86, 87,
-  88, 89, 90, 91, 92, 93, 94, 95,
-  96, 97, 98, 99, 100, 101, 102, 103,
-  104, 105, 106, 107, 108, 109, 110, 111,
-  112, 113, 114, 115, 116, 117, 118, 119,
-  120, 121, 122, 123, 124, 125, 126, 127,
-};
-
 static void check_set(const char *name, unsigned int capacity,
-                      unsigned int *s, size_t slen)
+                      const unsigned int *s, size_t slen)
 {
   struct uint_bset bset;
   size_t i, j;
@@ -140,14 +120,27 @@ static void check_set(const char *name, unsigned int capacity,
   Curl_uint_bset_destroy(&bset);
 }
 
-static void unit_stop(void)
+static CURLcode test_unit3211(char *arg)
 {
-}
+  UNITTEST_BEGIN_SIMPLE
 
-
-UNITTEST_START
+  static const unsigned int s1[] = {  /* spread numbers, some at slot edges */
+    0, 1, 4, 17, 63, 64, 65, 66,
+    90, 99,
+  };
+  static const unsigned int s2[] = { /* set with all bits in slot1 set */
+    64, 65, 66, 67, 68, 69, 70, 71,
+    72, 73, 74, 75, 76, 77, 78, 79,
+    80, 81, 82, 83, 84, 85, 86, 87,
+    88, 89, 90, 91, 92, 93, 94, 95,
+    96, 97, 98, 99, 100, 101, 102, 103,
+    104, 105, 106, 107, 108, 109, 110, 111,
+    112, 113, 114, 115, 116, 117, 118, 119,
+    120, 121, 122, 123, 124, 125, 126, 127,
+  };
 
   check_set("s1", 100, s1, CURL_ARRAYSIZE(s1));
   check_set("s2", 1000, s2, CURL_ARRAYSIZE(s2));
 
-UNITTEST_STOP
+  UNITTEST_END_SIMPLE
+}