pgsql: Factor out encoding specific tests for json

Factor out encoding specific tests for json

This lets us remove the large alternative results files for the main
json and jsonb tests, which makes modifying those tests simpler for
committers and patch submitters.

Backpatch to 9.4 for jsonb and 9.3 for json.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/b6363772fd5f07dcfff2b4869765705ac9633950

Modified Files
--------------
src/test/regress/expected/json.out | 113 +-
src/test/regress/expected/json_1.out | 1726 -------------
src/test/regress/expected/json_encoding.out | 247 ++
src/test/regress/expected/json_encoding_1.out | 243 ++
src/test/regress/expected/jsonb.out | 131 +-
src/test/regress/expected/jsonb_1.out | 3336 -------------------------
src/test/regress/parallel_schedule | 2 +-
src/test/regress/serial_schedule | 1 +
src/test/regress/sql/json.sql | 28 +-
src/test/regress/sql/json_encoding.sql | 68 +
src/test/regress/sql/jsonb.sql | 31 +-
11 files changed, 564 insertions(+), 5362 deletions(-)