pgsql: Update some more ObjectType switch statements to not have defaul

Update some more ObjectType switch statements to not have default

This allows the compiler to complain if a case has been missed.  In
these instances, the tradeoff of having to list a few unneeded cases
to silence the compiler seems better than the risk of actually missing
one.

Discussion: https://www.postgresql.org/message-id/flat/fce5c98a-45da-19e7-dad0-21096bccd66e%40enterprisedb.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/aca992040951c7665f1701cd25d48808eda7a809

Modified Files
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src/backend/catalog/objectaddress.c | 26 +++++++++++++++----------
src/backend/commands/dropcmds.c     | 39 +++++++++++++++++++++++++++++++++++--
2 files changed, 53 insertions(+), 12 deletions(-)