fix(api-cardano-db-hasura): retry initialization of data fetcher

This fetcher can fail on initial startup as it depends on Ogmios being up and running. Retry
this operation using exponential backoff, limited to 15 seconds, indefinitely.

packages/api-cardano-db-hasura/src/HasuraClient.ts

@@ -124,7 +124,18 @@ export class HasuraClient {
       )
     })
     this.logger.debug({ module: 'HasuraClient' }, 'graphql-engine setup')
-    await this.adaPotsToCalculateSupplyFetcher.initialize()
+    await pRetry(async () => {
+      await this.adaPotsToCalculateSupplyFetcher.initialize()
+    }, {
+      factor: 1.1,
+      forever: true,
+      maxTimeout: 15000,
+      onFailedAttempt: util.onFailedAttemptFor(
+        'Initializing data fetchers',
+        this.logger
+      )
+    })
+    this.logger.debug({ module: 'HasuraClient' }, 'Data fetchers initialized')
     this.state = 'initialized'
     this.logger.info({ module: 'HasuraClient' }, 'Initialized')
   }