to_timestamp(double) gives different results depending on scalar/vectorized call context

[findepi]

Describe the bug

We have this in SLT tests

query PPP
SELECT to_timestamp(1.1) as c1, ...
----
1970-01-01T00:00:01.100 ...

and indeed it works in CLI

> SELECT to_timestamp(1.1);
+----------------------------+
| to_timestamp(Float64(1.1)) |
+----------------------------+
| 1970-01-01T00:00:01.100    |
+----------------------------+

unless the value is not result of constant folding

> SELECT to_timestamp(x) FROM (VALUES (1.1), (NULL)) t(x);
+-------------------------------+
| to_timestamp(t.x)             |
+-------------------------------+
| 1970-01-01T00:00:00.000000001 |
| NULL                          |
+-------------------------------+

To Reproduce

No response

Expected behavior

Same result

Additional context

• Different result of double to timestamp(9) cast when source value is constant #16636
• Different result of decimal to timestamp cast when source value is constant #16531
• Ensure to_timestamp behaves consistently with PostgreSQL #13351