Add async tasks

[joshbwlng]

Change-type: minor

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Spec: https://balena.fibery.io/Inputs/Research/PineJS-Async-Tasks-483

Testing locally:

docker-compose -f docker-compose.npm-test.yml up -d
export DATABASE_URL=postgres://docker:docker@localhost:5431/postgres
export PINEJS_QUEUE_CONCURRENCY=1
TZ=UTC npm run mocha test/08-tasks.test.ts

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Follow-ups:

• Add support for FOR UPDATE SKIP LOCKED to abstractSql and update the polling query for tasks to be written in abstractSql
• Add generic .on('notification') handler for listening for db events, such as new task inserts

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Depends on:

• https://github.com/balena-io-modules/sbvr-types/pull/106
• https://github.com/balena-io/pinejs/pull/775
• https://github.com/balena-io-modules/abstract-sql-to-typescript/pull/76
• https://github.com/balena-io-modules/pinejs-client-js/pull/167