Current testing technique does not catch some cases when the return value is not valid for given type

[findepi]

io.prestosql.sql.query.QueryAssertions#expression(java.lang.String) + matches can pass eveb when value is not correct for given type: eg not properly truncated (char with trailing spaces), or not properly rounded (timestamp with not max precision).

See https://github.com/prestosql/presto/issues/5736#issuecomment-718846167 for example.

Implementation plan:

Add checks within (explicitly or implicitly) io.prestosql.spi.type.Type#getObjectValue implementations:

• [ ] decimal scale, precision checks
• [x] char length check, padding spaces stripped check https://github.com/prestosql/presto/pull/5743
• [x] varchar length check https://github.com/prestosql/presto/pull/5743
• [x] time and time with time zone precision checks
• [x] timestamp and timestamp with time zone precision checks https://github.com/prestosql/presto/pull/5742 (https://github.com/prestosql/presto/pull/5742/commits/ba17097e495544fdb633c327a8c548f5858f54d4)

[findepi]

I updated the description with the checklist. @prestosql/maintainers please update if any more checks we should add come to your mind.

[findepi]

We still need to add checks for decimal. So far @ksobolew added a check flagging "negative zero", but we also need precision/scale checks.

cc @ksobolew @lukasz-stec