pgsql: Add more tests for COPY with incorrect option combinations

Add more tests for COPY with incorrect option combinations

Based on the existing coverage report, some combinations were not
checked at all, so add some tests to do so.  Spotted while looking at
the area.

Discussion: https://postgr.es/m/Y2DNm9u7hzIxCXHn@paquier.xyz

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/451d1164b9d0cce6acd0b3d0790f09db4c56be0a

Modified Files
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src/test/regress/expected/copy2.out | 17 +++++++++++++++++
src/test/regress/sql/copy2.sql      | 10 ++++++++++
2 files changed, 27 insertions(+)