* Instantiate a new wasm string to convert JSON value to BigInt
* Implement remaining json host APIs
* Upgrade graph-ts and graph-cli in test example subgraph
* Handle null context for dataSource context host API
* Use JSONBig for parsing JSON strings
* Implement data source templates
* Remove optional param from wasm instantiate
* Add all types for solidity to typescript mapping
* Set contract address in context for data source templates
* Implement block handlers for data source templates
* Handle BigNumber event params in watchers
* Customize decimal according to limits of IEEE-754 decimal128
* Add definition for custom scalar BigDecimal
* Add a test case to eden test to call the block handler
* Add a block handler in example subgraph and call it in a watcher
* Use an array map to call all the block handlers for a contract
* Await on all the promises returned by block handlers map
* Implement store get api without blockHash and blockNumber
* Pass database instance to GraphWatcher
* Implement store set without block data
* Store blockHash and blockNumber in database entity table
* Implement getting entity in subgraph from store.get
* Add block data present in postgraphile
* Pass db and context to instantiate method in tests
* GQL API in graph-test-watcher to test store.set
* Remove contract address from subgraph file
* Fix block in dummy event data
* Pass just blockHash to get an entity from the database
* Review changes and add TODOs
Co-authored-by: prathamesh <prathamesh.musale0@gmail.com>
* Invoke subgraph handler in watcher event processing
* Fix error when invoking subgraph handler
* Parse events using event signature specified in subgraph yaml
* Use contract abi to parse event params
* Invoke event handler based on event signature
* Fill event with block and transaction data
* Comment missing fields in block and transaction data
* Perform eth_call and get result in js import
* Use dummy value for eth_call
* Called handler in wasm with event param
* Implement passing event to subgraph handler function
* Use generated event class Test for passing to handler
* Pass event params to handler
Co-authored-by: nabarun <nabarun@deepstacksoft.com>