test/static: add a seed corpus for decimal_to_int64_fuzzer NO_DOC=seed corpus NO_CHANGELOG=seed corpus NO_TEST=seed corpus (cherry picked from commit 4894863ec313f62df8a2eac5dd06deaa1beaf305)

test/fuzz: add fuzzing test for decoding decimals NO_DOC=testing NO_CHANGELOG=testing (cherry picked from commit 4deadeb84e2b3011018eadbbfe2d1e798d95fe5f)

test/static: add a seed corpus for IPROTO decoders NO_DOC=seed corpus NO_CHANGELOG=seed corpus NO_TEST=seed corpus (cherry picked from commit 4b5fb95396efb3c5f84a3566ae4ba510ac449690)

test/fuzz: add fuzzing tests for IPROTO decoders Examples of IPROTO decoding issues: #3900, #1928, #6781. Patch adds a number of fuzzing tests that covers IPROTO decoding: - xrow_decode_auth - xrow_decode_begin - xrow_decode_call - xrow_decode_dml - xrow_decode_id - xrow_decode_raft - xrow_decode_sql - xrow_decode_watch - xrow_greeting_decode NO_DOC=testing NO_CHANGELOG=testing (cherry picked from commit 46cacf35bd6454102a6f8e3e47281f66cc3fdd8c)

test/fuzz: collect and print Lua metrics Fuzzing test for LuaJIT generates random Lua programs and executes them. We want to build a fuzzing test that will produce Lua programs that will not contain semantic errors and will trigger as much as possible components in LuaJIT. This proposed patch introduces metrics that gathered after running the test. LuaJIT metrics gathered using LuaJIT getmetrics module [1]. All gathered metrics test will output after running with a finite number of runs or finite duration of time (options `-runs` and `-max_total_time`) or after sending SIGUSR1 to a test process. ``` $ ./build/test/fuzz/luaL_loadbuffer/luaL_loadbuffer_fuzzer -runs=1000 <snipped> Done 1000 runs in 1 second(s) Total number of samples: 1000 Total number of samples with errors: 438 (43%) Total number of samples with recorded traces: 87 (8%) Total number of samples with snap restores: 30 (3%) Total number of samples with abort traces: 55 (5%) ``` 1. https://www.tarantool.io/en/doc/latest/reference/tooling/luajit_getmetrics/#getmetrics-c-api NO_CHANGELOG=testing NO_DOC=testing (cherry picked from commit 430fa6a2ae173845c4ae78fd07c5801cb261433f)