Ensuring chronological execution of hooks and checkpointing (#264)

* Subscribe to hooks queue in existing watchers

* Change naming strategy for generated get and save functions

* Push checkpointing job after post-block hook job completed

* Using hooks status to ensure their chronological execution

* Add default indices to IPLDBlock table

* Add kind parameter to getState GQL API

* Add checkpoint CLI

* Add blockHash arg to checkpoint CLI and update codegen docs

* Print out block hash for checkpoint CLI

* Use log from debug for logging

* Filter using contract at start in hierarchical query

* Make kind argument to prepare IPLDBlock required

packages/codegen/README.md

@@ -73,6 +73,8 @@
 
 * Create the databases configured in `environments/local.toml`.
 
+* Update the derived state checkpoint settings in `environments/local.toml`.
+
 ### Customize
 
 * Indexing on an event:
@@ -81,6 +83,8 @@
 
   * Edit the custom hook function `handleBlock` (triggered on a block) in `src/hooks.ts` to save `IPLDBlock`s using the `Indexer` object.
 
+  * Edit the custom hook function `genesisHook` (triggered on watch-contract) in `src/hooks.ts` to save a genesis checkpoint `IPLDBlock` using the `Indexer` object.
+
   * The existing example hooks in `src/hooks.ts` are for an `ERC20` contract.
 
 ### Run
@@ -114,7 +118,13 @@
   * To fill a block range:
 
     ```bash
-    yarn fill --startBlock <from-block> --endBlock <to-block>
+    yarn fill --start-block <from-block> --end-block <to-block>
+    ```
+
+  * To create a checkpoint for a contract:
+
+    ```bash
+    yarn checkpoint --address <contract-address> --block-hash [block-hash]
     ```
 
 ## Known Issues