feat: make RUST_LOG parametrized (#11)

## What ❔
Customize RUST_LOG variable

## Why ❔
There're lot of packages used for EN and each of them has their own
logging verbosity

## Checklist

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- [ ] PR title corresponds to the body of PR (we generate changelog
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- [ ] Documentation comments have been added / updated.

defaults/main.yml

@@ -80,7 +80,7 @@ rpc_http_port: 3060
 rpc_ws_port: 3061
 healthcheck_port: 3081
 metrics_port: 3082
-log_verbosity: info
+rust_log: zksync_external_node=info,zksync_core=info,zksync_core::sync_layer=info,zksync_server=info,zksync_prover=info,zksync_contract_verifier=info,zksync_dal=info,zksync_eth_client=info,zksync_storage=info,zksync_db_manager=info,zksync_merkle_tree=info,zksync_state=info,zksync_utils=info,zksync_types=info,loadnext=info,dev_ticker=info,vm=info,block_sizes_test=info,zksync_verification_key_generator_and_server=info,zksync_object_store=info,setup_key_generator_and_server=info,zksync_circuit_synthesizer=info,zksync_queued_job_processor=info,zksync_health_check=info
 
 # Monitoring options section
 enable_monitoring: false

templates/docker-compose.yaml.j2

@@ -91,7 +91,7 @@ services:
       DATABASE_POOL_SIZE: 200
       EN_MAX_BLOCKS_PER_TREE_BATCH: 200
       MISC_LOG_FORMAT: json
-      RUST_LOG: zksync_external_node={{ log_verbosity }}
+      RUST_LOG: {{ rust_log }}
     healthcheck:
       test: [ "CMD", "curl", "-f", "http://localhost:{{ healthcheck_port }}/health" ]
       interval: 1m