pgAdmin 4 commit: Improve the explain plan details by showing popup ins

Improve the explain plan details by showing popup instead of tooltip on clicking of the specified node. Fixes #5488

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=6589f82e777e2adef1433c9859121c98a029f1eb
Author: Aditya Toshniwal <aditya.toshniwal@enterprisedb.com>

Modified Files
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docs/en_US/images/query_output_explain_details.png | Bin 179156 -> 213690 bytes
docs/en_US/images/query_toolbar_explain.png        | Bin 173583 -> 195038 bytes
docs/en_US/query_tool.rst                          |  10 +-
docs/en_US/release_notes_4_30.rst                  |   1 +
web/pgadmin/misc/static/explain/js/explain.js      | 110 ++++++++-------------
.../misc/static/explain/js/explain_statistics.js   |  46 ++++-----
web/pgadmin/misc/static/explain/scss/_explain.scss |  25 ++++-
web/pgadmin/static/scss/_bootstrap.overrides.scss  |   1 +
.../misc/explain/explain_statistics_spec.js        |  60 ++++-------
9 files changed, 106 insertions(+), 147 deletions(-)