pgAdmin 4 commit: Improve code coverage and API test cases for the CAST

Improve code coverage and API test cases for the CAST module. Fixes #5049.

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=4ab3bbeb82ca282327b1823205f9f9b2376ff396
Author: Yogesh Mahajan <yogesh(dot)mahajan(at)enterprisedb(dot)com>

Modified Files
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docs/en_US/release_notes_4_18.rst | 1 +
.../databases/casts/tests/cast_test_data.json | 763 +++++++++++++++++++++
.../databases/casts/tests/test_cast_create.py | 76 ++
.../casts/tests/test_cast_create_get_functions.py | 62 ++
...st_cast_add.py => test_cast_create_get_type.py} | 48 +-
.../databases/casts/tests/test_cast_delete.py | 53 +-
.../casts/tests/test_cast_delete_multiple.py | 55 +-
.../servers/databases/casts/tests/test_cast_get.py | 57 +-
.../tests/test_cast_get_dependencies_dependent.py | 80 +++
.../databases/casts/tests/test_cast_get_node.py | 95 +++
.../databases/casts/tests/test_cast_get_sql.py | 81 +++
.../servers/databases/casts/tests/test_cast_put.py | 53 +-
.../servers/databases/casts/tests/utils.py | 160 ++++-
13 files changed, 1471 insertions(+), 113 deletions(-)