test: update parameters in sql-tap tests

A long time ago (as Mergen Imeev told), API for Tarantool's
storage engines was not unified, and SQL tests could be
successfully executed on one engine and be broken on another. Due
to this, some SQL tests were parameterized by a single engine. Now
all SQL tests can be successfully executed on both engines (vinyl
and memtx). The patch updates a config for an `sql-tap` test suite
and allows parameterization by both engines.

Required by the following commit.

NO_CHANGELOG=testing
NO_DOC=testing
NO_TEST=testing

Author: ligurio

test/sql-tap/engine.cfg

@@ -1,46 +1,4 @@
 {
-    "analyze9.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "collation_unicode.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "in2.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "delete3.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "sort.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "gh-3083-ephemeral-unref-tuples.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "gh-3332-tuple-format-leak.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "gh-6164-uuid-follow-ups.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "metatypes.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "decimal.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "gh-6239-quote-with-double-arg.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "built-in-functions.test.lua": {
-        "memtx": {"engine": "memtx"}
-    },
-    "gh-6157-unnecessary-free-on-string.test.lua": {},
-    "gh-6376-wrong-double-to-dec-cmp.test.lua": {},
-    "gh-4077-iproto-execute-no-bind.test.lua": {},
-    "gh-6375-assert-on-unsupported-ext.test.lua": {},
-    "gh-6485-bugs-in-decimal.test.lua": {},
-    "gh-6113-assert-in-hex-on-zeroblob.test.lua": {},
     "*": {
         "memtx": {"engine": "memtx"},
         "vinyl": {"engine": "vinyl"}