pgsql: Refactor function parse_subscription_options.

Refactor function parse_subscription_options.

Instead of using multiple parameters in parse_subscription_options
function signature, use the struct SubOpts that encapsulate all the
subscription options and their values. It will be useful for future work
where we need to add other options in the subscription. Also, use bitmaps
to pass the supported and retrieve the specified options much like the way
it is done in the commit a3dc926009.

Author: Bharath Rupireddy
Reviewed-By: Peter Smith, Amit Kapila, Alvaro Herrera
Discussion: https://postgr.es/m/CALj2ACXtoQczfNsDQWobypVvHbX2DtgEHn8DawS0eGFwuo72kw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/8aafb02616753f5c6c90bbc567636b73c0cbb9d4

Modified Files
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src/backend/commands/subscriptioncmds.c | 439 +++++++++++++++-----------------
src/tools/pgindent/typedefs.list        |   1 +
2 files changed, 207 insertions(+), 233 deletions(-)