Rely on gocbcore retries where possible

What's the issue?

Currently, we sometimes use the tools-common Retryer alongside the gocbcore retryer or just the tools-common retrying. On this ticket it was proposed we only use the gocbcore retryers. This ticket aims to address that.

Places in code where the use of tools-common retryers was found:

• https://github.com/couchbase/backup/blob/aaa17043cd533e61980aa252477d0b78f63263ae/couchbase/query.go#L87-L111
• https://github.com/couchbase/backup/blob/aaa17043cd533e61980aa252477d0b78f63263ae/couchbase/analytics.go#L88-L107
• https://github.com/couchbase/backup/blob/aaa17043cd533e61980aa252477d0b78f63263ae/couchbase/item_count.go#L143C2-L146
• https://github.com/couchbase/backup/blob/aaa17043cd533e61980aa252477d0b78f63263ae/couchbase/sequence_numbers.go#L143C5-L145

What's the fix?

We need to determine whether it's possible to use the gocbcore retry in these places and any others and implement it if so.