[FEA] libcudf read json lines mode support nrows

Support row-count-restricted reads when reading json in `lines` mode.

polars supports this, so we should at least consider supporting it via libcudf.

**Describe the solution you'd like**

An option to specify the number of rows to read for lines mode.
(we should raise if this parameter is used when lines=False)

**Describe alternatives you've considered**

We can post-filter the read dataframe, but that potentially does much more work than necessary.