Addon Manager: Begin UI redesign

Migrate to a UI that looks more like other software package managers, giving
more space to each addon by hiding the list when an addon is selected, and
providing a "back" button to get back.

Implements a two-style view option for the list of addons: expanded and
condensed, via a delegate that provides the drawing function for each row in
the table based on two different widget designs.

src/Mod/AddonManager/compact_view.py

@@ -0,0 +1,84 @@
+# -*- coding: utf-8 -*-
+
+################################################################################
+## Form generated from reading UI file 'compact_view.ui'
+##
+## Created by: Qt User Interface Compiler version 5.15.1
+##
+## WARNING! All changes made in this file will be lost when recompiling UI file!
+################################################################################
+
+from PySide2.QtCore import *
+from PySide2.QtGui import *
+from PySide2.QtWidgets import *
+
+
+class Ui_CompactView(object):
+    def setupUi(self, CompactView):
+        if not CompactView.objectName():
+            CompactView.setObjectName(u"CompactView")
+        CompactView.resize(489, 16)
+        sizePolicy = QSizePolicy(QSizePolicy.Expanding, QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(CompactView.sizePolicy().hasHeightForWidth())
+        CompactView.setSizePolicy(sizePolicy)
+        self.horizontalLayout_2 = QHBoxLayout(CompactView)
+        self.horizontalLayout_2.setObjectName(u"horizontalLayout_2")
+        self.horizontalLayout_2.setSizeConstraint(QLayout.SetNoConstraint)
+        self.horizontalLayout_2.setContentsMargins(3, 0, 9, 0)
+        self.labelIcon = QLabel(CompactView)
+        self.labelIcon.setObjectName(u"labelIcon")
+        sizePolicy1 = QSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)
+        sizePolicy1.setHorizontalStretch(0)
+        sizePolicy1.setVerticalStretch(0)
+        sizePolicy1.setHeightForWidth(self.labelIcon.sizePolicy().hasHeightForWidth())
+        self.labelIcon.setSizePolicy(sizePolicy1)
+        self.labelIcon.setMinimumSize(QSize(16, 16))
+        self.labelIcon.setBaseSize(QSize(16, 16))
+
+        self.horizontalLayout_2.addWidget(self.labelIcon)
+
+        self.labelPackageName = QLabel(CompactView)
+        self.labelPackageName.setObjectName(u"labelPackageName")
+
+        self.horizontalLayout_2.addWidget(self.labelPackageName)
+
+        self.labelVersion = QLabel(CompactView)
+        self.labelVersion.setObjectName(u"labelVersion")
+
+        self.horizontalLayout_2.addWidget(self.labelVersion)
+
+        self.labelDescription = QLabel(CompactView)
+        self.labelDescription.setObjectName(u"labelDescription")
+        sizePolicy2 = QSizePolicy(QSizePolicy.MinimumExpanding, QSizePolicy.Preferred)
+        sizePolicy2.setHorizontalStretch(0)
+        sizePolicy2.setVerticalStretch(0)
+        sizePolicy2.setHeightForWidth(self.labelDescription.sizePolicy().hasHeightForWidth())
+        self.labelDescription.setSizePolicy(sizePolicy2)
+        self.labelDescription.setTextFormat(Qt.PlainText)
+        self.labelDescription.setWordWrap(False)
+        self.labelDescription.setTextInteractionFlags(Qt.TextSelectableByMouse)
+
+        self.horizontalLayout_2.addWidget(self.labelDescription)
+
+        self.labelStatus = QLabel(CompactView)
+        self.labelStatus.setObjectName(u"labelStatus")
+
+        self.horizontalLayout_2.addWidget(self.labelStatus)
+
+
+        self.retranslateUi(CompactView)
+
+        QMetaObject.connectSlotsByName(CompactView)
+    # setupUi
+
+    def retranslateUi(self, CompactView):
+        CompactView.setWindowTitle(QCoreApplication.translate("CompactView", u"Form", None))
+        self.labelIcon.setText(QCoreApplication.translate("CompactView", u"Icon", None))
+        self.labelPackageName.setText(QCoreApplication.translate("CompactView", u"<b>Package Name</b>", None))
+        self.labelVersion.setText(QCoreApplication.translate("CompactView", u"Version", None))
+        self.labelDescription.setText(QCoreApplication.translate("CompactView", u"Description", None))
+        self.labelStatus.setText(QCoreApplication.translate("CompactView", u"UpdateAvailable", None))
+    # retranslateUi
+