pgAdmin 4 commit: Support running on systems without a system tray.Fix

Support running on systems without a system tray. Fixes #3316

Branch
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master

Details
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https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=765a88addfdf469dfb311aa6310e9c8aefbef223
Author: Akshay Joshi <akshay.joshi@enterprisedb.com>

Modified Files
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docs/en_US/release_notes_3_2.rst |   1 +
runtime/.gitignore               |  13 +--
runtime/FloatingWindow.cpp       | 103 +++++++++++++++++++++++
runtime/FloatingWindow.h         |  56 +++++++++++++
runtime/FloatingWindow.ui        | 155 ++++++++++++++++++++++++++++++++++
runtime/MenuActions.cpp          | 129 ++++++++++++++++++++++++++++
runtime/MenuActions.h            |  46 ++++++++++
runtime/TrayIcon.cpp             | 177 +++------------------------------------
runtime/TrayIcon.h               |  27 ++----
runtime/pgAdmin4.cpp             |  58 ++++++++++---
runtime/pgAdmin4.pro             |  14 ++--
11 files changed, 567 insertions(+), 212 deletions(-)