test: add luaL_loadbuffer_fuzzer NO_CHANGELOG=add new test NO_DOC=add new test

ci: update version of checkout action Fix the following warning: NO_WRAP Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: actions/checkout NO_WRAP Fixes tarantool/tarantool-qa#279 NO_DOC=ci NO_TEST=ci NO_CHANGELOG=ci

ci: update version of upload-artifact action Fix the following warning: NO_WRAP Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: actions/upload-artifact NO_WRAP Fixes tarantool/tarantool-qa#280 NO_DOC=ci NO_TEST=ci NO_CHANGELOG=ci

txn: account started, committed, and rolled back transactions This commit fixes BEGIN, COMMIT, and ROLLBACK counters in the box.stat() output. Before this commit, they always showed 0. Now, they report the number of started, committed, and rolled back transactions, respectively. Closes #7583 NO_DOC=bug fix

box: panic if snapshot has no system spaces during recovery Currently, if a snapshot contains some correct entries, but doesn't include system spaces, Tarantool crashes with segmentation fault, or for Debug build: void diag_raise(): Assertion `e != NULL' failed. This happens because memtx_engine_recover_snapshot returns -1, while diag is not set. Let's panic instead of a crash. Closes #7800 NO_DOC=bugfix