pgsql: Expand EPQ tests for UPDATEs and DELETEs

Expand EPQ tests for UPDATEs and DELETEs

Previously there was basically no coverage for UPDATEs encountering
deleted rows, and no coverage for DELETE having to perform EPQ. That's
problematic for an upcoming commit in which EPQ is tought to integrate
with tableams. Also, there was no test for UPDATE to encounter a row
UPDATEd into another partition.

Author: Andres Freund

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/cdcffe2263215eef9078ce97e6c9adece8ed1910

Modified Files
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src/test/isolation/expected/eval-plan-qual.out | 252 ++++++++++++++++++++-
.../isolation/expected/partition-key-update-1.out | 10 +
src/test/isolation/specs/eval-plan-qual.spec | 35 ++-
.../isolation/specs/partition-key-update-1.spec | 1 +
4 files changed, 288 insertions(+), 10 deletions(-)