Support type coercion between timestamp and unixtime

[niebayes]

Is your feature request related to a problem or challenge?

Say there's a table consisting of a timestamp column with the precision seconds. If we can support type coercion between timestamp and unixtime, a query SELECT * FROM tbl WHERE ts > 1723527660 would be regarded legal and there's no need to wrap the unixtime with the function from_unixtime.

Describe the solution you'd like

Add a cast path between timestamp and unixtime, and try to cast a integer to a certain timestamp type when building a plan. Reports an error when such a cast fails.

Describe alternatives you've considered

No response

Additional context

No response

[Omega359]

related: #11040
tangential (date & int64): #12342