pgAdmin 4 commit: 1) Added ProjectSet icon for explain module. Fixes #2

1) Added ProjectSet icon for explain module. Fixes #2706
2) Added Gather Merge, Named Tuple Store Scan and Table Function Scan icon for explain module. Fixes #2828

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=bdff046c572796d1fbf47f22c6f70f3507d48b82

Modified Files
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docs/en_US/release_notes.rst                        |  1 +
docs/en_US/release_notes_4_13.rst                   | 21 +++++++++++++++++++++
.../misc/static/explain/img/ex_gather_merge.svg     |  1 +
.../static/explain/img/ex_named_tuplestore_scan.svg |  1 +
.../misc/static/explain/img/ex_projectset.svg       |  1 +
.../misc/static/explain/img/ex_table_func_scan.svg  |  1 +
web/pgadmin/misc/static/explain/js/image_maper.js   | 16 ++++++++++++++++
7 files changed, 42 insertions(+)