feat: add parameter for set log verbosity and json format (#10)

## What ❔
Logs in json format and option for set verbosity level for rust 

## Why ❔
It can be useful for specify verbose level.

## Checklist

<!-- Check your PR fulfills the following items. -->
<!-- For draft PRs check the boxes as you complete them. -->

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

templates/docker-compose.yaml.j2

@@ -90,7 +90,8 @@ services:
       CHAIN_STATE_KEEPER_VALIDATION_COMPUTATIONAL_GAS_LIMIT: 2000000
       DATABASE_POOL_SIZE: 200
       EN_MAX_BLOCKS_PER_TREE_BATCH: 200
-      RUST_LOG: zksync_core=debug,zksync_dal=info,zksync_eth_client=info,zksync_merkle_tree=info,zksync_storage=info,zksync_state=debug,zksync_types=info,vm=info,zksync_external_node=info,zksync_utils=debug
+      MISC_LOG_FORMAT: json
+      RUST_LOG: zksync_external_node={{ log_verbosity }}
     healthcheck:
       test: [ "CMD", "curl", "-f", "http://localhost:{{ healthcheck_port }}/health" ]
       interval: 1m