Fix off-by-one error in superblock mode (#3221)

Fixes #3212.

Long literal and match lengths had an off-by-one error in ZSTD_getSequenceLength.
Fix the off-by-one error, and add a golden compression test that catches the bug.
Also run all the golden tests in the cli-tests framework.

tests/cli-tests/dictionaries/golden.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -e
+
+GOLDEN_COMP_DIR="$ZSTD_REPO_DIR/tests/golden-compression/"
+GOLDEN_DICT_DIR="$ZSTD_REPO_DIR/tests/golden-dictionaries/"
+
+zstd -D "$GOLDEN_DICT_DIR/http-dict-missing-symbols" "$GOLDEN_COMP_DIR/http" -o http.zst
+zstd -D "$GOLDEN_DICT_DIR/http-dict-missing-symbols" -t http.zst