v0.23.0

The Graph Node internals are being heavily refactored to prepare it for the multichain future.
In the meantime, here are the changes for this release:

• The GRAPH_ETH_CALL_BY_NUMBER environment variable has been removed. Graph Node requires an
  Ethereum client that supports EIP-1898, which all major clients support.
• Added support for IPFS versions larger than 0.4. Several changes to make
  graph-node more tolerant of slow/flaky IPFS nodes.
• Added Ethereum ABI encoding and decoding functionality #2348.
• Experimental support for configuration files, see the documentation here.
• Better PoI performance #2329.
• Improve grafting performance and robustness by copying in batches #2293.
• Subgraph metadata storage has been simplified and reorganized. External
  tools (e.g., Grafana dashboards) that access the database directly will need to be updated.
• Ordering in GraphQL queries is now truly reversible
  #2214
• The GRAPH_SQL_STATEMENT_TIMEOUT environment variable can be used to
  enforce a timeout for individual SQL queries that are run in the course of
  processing a GraphQL query
  #2285
• Using ethereum.call in mappings in globals is deprecated

Graphman

Graphman is a CLI tool to manage your subgraphs. It is now included in the Docker container
#2289. And new commands have been added:

• graphman copy can copy subgraphs across DB shards #2313.
• graphman rewind to rewind a deployment to a given block #2373.
• graphman query to log info about a GraphQL query #2206.
• graphman create to create a subgraph name #2419.

Metrics

• The deployment_blocks_behind metric has been removed, and a
  deployment_head metric has been added. To see how far a deployment is
  behind, use the difference between ethereum_chain_head_number and
  deployment_head.
• The trigger_type label was removed from the metric deployment_trigger_processing_duration.