Send heartbeat when downloading spooled segments

[azawlocki-sbdt]

Description

Resolves #554

Trino can abandon a query if the client is silent for too long. When results are delivered via the spooling protocol, downloading a segment from S3/MinIO blocks the client and may cause query timeout if the download takes too long (the timeout is set in Trino configuration, current default is 5 min).

This PR implements a heartbeat mechanism: a background thread is sending periodic HEAD requests to the coordinator's nextUri while a spooled segment is being downloaded. The heartbeat is started and stopped around each SpooledSegment.data fetch inside SegmentIterator._load_next_segment(). Heartbeat thread is not started if spooling is not used.

Heartbeat requests are emitted in 30s intervals by default. Custom interval can be set using the new heartbeat_interval param for Connection. Setting it to None disables heartbeat.

Unit tests are added in the new module tests/unit/test_client_spooling.py.
An integration test is added in tests/integration/test_dbapi_integration.py.

Release notes

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* Fix some things. ({issue}`issuenumber`)

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[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla