pgsql: Rename libpq test programs with libpq_ prefix

Rename libpq test programs with libpq_ prefix

The testclient and uri-regress programs in the libpq test suite had
quite generic names which didn't convey much meaning. Since they are
installed as part of the MSVC test runs, ensure that their purpose
is a little bit clearer by renaming with a libpq_ prefix. While at
it rename uri-regress to uri_regress to avoid mixing dash and under-
score in the same filename.

Reported-by: Noah Misch <noah(at)leadboat(dot)com>
Discussion: https://postgr.es/m/20220501080706.GA1542365@rfd.leadboat.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0432490d290f679cad773ce4735e8769e2c4db75

Modified Files
--------------
src/interfaces/libpq/t/001_uri.pl | 30 +++++++++++-----------
src/interfaces/libpq/t/002_api.pl | 2 +-
src/interfaces/libpq/test/.gitignore | 4 +--
src/interfaces/libpq/test/Makefile | 2 +-
.../test/{testclient.c => libpq_testclient.c} | 4 +--
.../test/{uri-regress.c => libpq_uri_regress.c} | 8 +++---
src/tools/msvc/Mkvcbuild.pm | 8 +++---
7 files changed, 29 insertions(+), 29 deletions(-)