add storage benchmarks & base block benchmarks

add storage benchmarks (reads/writes times measurements).

docs/dev/weights-benchmarking.md

@@ -29,5 +29,17 @@ To cross-compile the benchmarks binary for armv7:
 ./scripts/cross-build-arm.sh --features runtime-benchmarks
 ```
 
-
 The cross compiled binary is generated here: `target/armv7-unknown-linux-gnueabihf/release/duniter`
+
+## Generate storage benchmarking
+
+1. Build binary fopr reference machien and copy it on reference machine
+2. Copy a DB on reference machine (on ssd), example: `scp -r -P 37015 tmp/t1 pi@192.168.1.188:/mnt/ssd1/duniter-v2s/`
+3. Run storage benchmarks command, example:
+
+```
+./duniter benchmark storage -d=/mnt/ssd1/duniter-v2s/t1 --chain=gdev --mul=2 --weight-path=. --state-version=1
+```
+
+4. Copy the generated file `paritydb_weights.rs` in the codebase in folder `runtime/common/src/weights/`.
+5. Commit changes and open an MR.