Add truncated statement indicator to mysql query sample events

[alexandre-normand]

What does this PR do?

This adds a boolean field to mysql query sample events so we can later surface this to users.

Motivation

We'd like to be able to surface when a statement has been truncated so we can advise uses on how to proceed to prevent truncation (which would be increasing performance_schema_max_sql_text_length).

Additional Notes

The detection of a truncated statement is done by checking for the presence of ... at the end of a statement. This works for all supported versions (as the tests show).

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[codecov]

Codecov Report

Merging #9620 (be68f48) into master (e71a245) will decrease coverage by 0.01%.
The diff coverage is 88.23%.

Flag	Coverage Δ
mysql	84.87% <88.23%> (-0.58%)	⬇️

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