file_fdw: Fix ANALYZE does not enforce REJECT_LIMIT with on_error 'ignore'

Hi,

When a file_fdw table is configured with on_error 'ignore' and a
reject_limit option,
SELECT queries properly abort with an ERROR once the number of bad rows
exceeds the limit.
However, ANALYZE silently ignores reject_limit, skips all
malformed rows, and finishes with a NOTICE.

Reproduce with this:

printf 'x\ny\n' > /tmp/fdw.csv

CREATE EXTENSION file_fdw;
CREATE SERVER fs FOREIGN DATA WRAPPER file_fdw;
CREATE FOREIGN TABLE ft_bad (a int) SERVER fs
 OPTIONS (filename '/tmp/fdw.csv', format 'csv',
        on_error 'ignore', reject_limit '1');

SELECT * FROM ft_bad;
ERROR:  skipped more than REJECT_LIMIT (1) rows due to data type
incompatibility
CONTEXT:  COPY ft_bad, line 2, column a: "y"

ANALYZE ft_bad;
NOTICE:  2 rows were skipped due to data type incompatibility

The fix is straightforward, we just add the same
cstate->opts.reject_limit check to
file_acquire_sample_rows(), just like we do for fileIterateForeignScan().

I thought about whether this is necessary at all or not (like it's not a
crash or anything, just not intended behavior at the very least), i'm
more into the first, thoughts ?

Regards,
Ayoub Kazar