database_observability: use tokenizer to extract table names as fallback

[cristiangreco]

PR Description

Improve parsing of table names from sql statements by using go-sqllexer as a fallback when the primary parser fails.

This means that there are chances we log a partial list of table names when the sql statement is truncated, but we're heading towards making alloy more resilient and mark statements as deemed unparseable.

Which issue(s) this PR fixes

n.a.

Notes to the Reviewer

PR Checklist

• CHANGELOG.md updated
• Documentation added
• Tests updated
• Config converters updated

[gaantunes]

I wonder if this new parser has the same issue that lists CTE tables as actual tables?

[cristiangreco]

I wonder if this new parser has the same issue that lists CTE tables as actual tables?

As chatted, CTE tables appear only in the list of tables touched by a particular query, not in the global list of tables.

But for a more direct answer, yes CTE tables should still be detected by the lexer.

[gaantunes]

I wonder if this new parser has the same issue that lists CTE tables as actual tables?

As chatted, CTE tables appear only in the list of tables touched by a particular query, not in the global list of tables.

But for a more direct answer, yes CTE tables should still be detected by the lexer.

We can seek classifying these as temp tables in a future iteration.