Java - add JNI FFI sync client to benchmarks

[Yury-Fridlyand]

The rust part based on code from #25 and #28, but get works. It is a sync client.

Repro instructions:

1. Check out java_benchmarks-jni branch
2. cd java
3. cargo build
4. ./gradlew :benchmarks:run

Notes:
C header file created automatically during compilation. To get it:

1. ./gradlew assemble
2. mv benchmarks/build/generated/sources/headers/java/main/javababushka_benchmarks_babushka_Jni.h .

Config	Action	Java FFI JNI	Jedis	Lettuce
1 client 10 concurrent	Get NE p50	0.164	0.024	0.046
1 client 10 concurrent	Get NE p90	0.194	0.027	0.054
1 client 10 concurrent	Get NE p99	0.212	0.039	0.092
1 client 10 concurrent	Get NE avg	0.177	0.025	0.049
1 client 10 concurrent	Get NE std	0.017	0.004	0.018
1 client 10 concurrent	Get E p50	0.169	0.025	0.047
1 client 10 concurrent	Get E p90	0.201	0.027	0.055
1 client 10 concurrent	Get E p99	0.219	0.039	0.095
1 client 10 concurrent	Get E avg	0.178	0.026	0.050
1 client 10 concurrent	Get E std	0.018	0.013	0.017
1 client 10 concurrent	Set p50	0.168	0.028	0.049
1 client 10 concurrent	Set p90	0.197	0.034	0.058
1 client 10 concurrent	Set p99	0.215	0.045	0.112
1 client 10 concurrent	Set avg	0.176	0.029	0.053
1 client 10 concurrent	Set std	0.017	0.010	0.038
2 client 10 concurrent	Get NE p50	0.189	0.024	0.044
2 client 10 concurrent	Get NE p90	0.197	0.025	0.050
2 client 10 concurrent	Get NE p99	0.213	0.034	0.063
2 client 10 concurrent	Get NE avg	0.180	0.025	0.045
2 client 10 concurrent	Get NE std	0.017	0.002	0.005
2 client 10 concurrent	Get E p50	0.195	0.025	0.045
2 client 10 concurrent	Get E p90	0.204	0.026	0.051
2 client 10 concurrent	Get E p99	0.221	0.035	0.064
2 client 10 concurrent	Get E avg	0.186	0.025	0.046
2 client 10 concurrent	Get E std	0.025	0.002	0.006
2 client 10 concurrent	Set p50	0.193	0.026	0.046
2 client 10 concurrent	Set p90	0.202	0.027	0.053
2 client 10 concurrent	Set p99	0.219	0.035	0.070
2 client 10 concurrent	Set avg	0.185	0.026	0.048
2 client 10 concurrent	Set std	0.017	0.002	0.006
1 client 100 concurrent	Get NE p50	0.165	0.024	0.045
1 client 100 concurrent	Get NE p90	0.185	0.025	0.047
1 client 100 concurrent	Get NE p99	0.202	0.033	0.056
1 client 100 concurrent	Get NE avg	0.174	0.025	0.046
1 client 100 concurrent	Get NE std	0.017	0.002	0.025
1 client 100 concurrent	Get E p50	0.171	0.025	0.045
1 client 100 concurrent	Get E p90	0.191	0.026	0.048
1 client 100 concurrent	Get E p99	0.209	0.034	0.057
1 client 100 concurrent	Get E avg	0.170	0.025	0.046
1 client 100 concurrent	Get E std	0.017	0.002	0.025
1 client 100 concurrent	Set p50	0.169	0.025	0.047
1 client 100 concurrent	Set p90	0.191	0.027	0.050
1 client 100 concurrent	Set p99	0.209	0.035	0.059
1 client 100 concurrent	Set avg	0.174	0.026	0.047
1 client 100 concurrent	Set std	0.017	0.002	0.025
2 client 100 concurrent	Get NE p50	0.173	0.025	0.044
2 client 100 concurrent	Get NE p90	0.186	0.026	0.047
2 client 100 concurrent	Get NE p99	0.206	0.034	0.056
2 client 100 concurrent	Get NE avg	0.170	0.025	0.045
2 client 100 concurrent	Get NE std	0.012	0.002	0.011
2 client 100 concurrent	Get E p50	0.175	0.024	0.045
2 client 100 concurrent	Get E p90	0.193	0.025	0.048
2 client 100 concurrent	Get E p99	0.211	0.033	0.057
2 client 100 concurrent	Get E avg	0.176	0.025	0.046
2 client 100 concurrent	Get E std	0.015	0.002	0.013
2 client 100 concurrent	Set p50	0.177	0.024	0.046
2 client 100 concurrent	Set p90	0.190	0.025	0.050
2 client 100 concurrent	Set p99	0.210	0.033	0.059
2 client 100 concurrent	Set avg	0.174	0.024	0.047
2 client 100 concurrent	Set std	0.013	0.002	0.012