SQL: ensure proper conversion of values when we format output in CLI

[elasticmachine]

Original comment by @imotov:

Currently we convert values using Objects.toString() that doesn't work for dates that are represented as longs and might not work for other value types as well. Converted NOCOMMITs LINK REDACTED and LINK REDACTED.

[astefan]

master (7.0.0): 7507af2
6.x (6.7.0): e80c5f3