HPCC-12677 Allow max CSV row size to be configured

The max CSV row size (default 10MB) prevents unbound CSV lines
causing problems (e.g. consuming all of memory).
10MB should be sufficient in 99% of cases, but sometimes a higher
limit is required, so allow the hard-limit to be configured via
a query #option('maxCsvRowSize', <MB>)

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
There is 1 other, "outputLimit", controlling the max size of a workunit output to Dali.
The other sizes (3 of them) are in bytes.

So unfortunately it's already inconsistent.

The others are very internal, so I could probably change without any ill-effect. FYI - they are "hdOutBufferSize", "hdInBufferSize" and "sort_max_deviance".
Their defaults are all multiples of Mb, but specified in bytes.

"outputLimit" is likely to be the one most likely to be being used.

I could:
a) ignore the pre-existing inconsistency, and make the new property "maxCsvRowMB" to hint at it being a MB setting.
b) Make them all consistent by changing all to have *MB names.
c) Change "outputLimit" and the new prop. "maxCsvRowSize" to bytes to be consistent with the other 3.

What do you reckon?

(3) is probably best, but that involves changing "outptuLimit" from meaning bytes where previously MB. (Though if there are queries relying on it, it will cause them to fail early, rather than cause Dali to fill up).