Deprecate legacy display panel for the Text Source

Change-Id: Iba99bf3caaca50519de6867768da92b5004b168c
Reworked Text Source display panel

Change-Id: I8100cab47ec1ca7aef082265c9d9e99d2bd09c30
Renamed pqTextWindowLocationWidget to pqTextLocationWidget

Change-Id: Iec86a4c3b7043ace4d2b0aa1b575951ee3f12940
Use new display panel for spreadsheet view

Change-Id: I3d4911065c0103798f16b02483bf8c7aa09b247e
Removed legacy display panel widgets

Change-Id: I055cf6f44e3607c40b62915a15bbf1843a2c592a
Changes in FontPropertyWidget and TextLocationWidget

FontPropertyWidget: Added opacity spinbox to control font opacity.
TextLocationWidget: Changed listening from the groupbox clicked()
signal to toggled() signal so that QtTesting tests can simply use
set_boolean command on the groupbox.

Change-Id: Ib7a45875e60d9f70f8a7d4e6f7318750c485e6a8
FIX: Fixed test using the new TextLocationWidget

QtTesting currently cannot record the event of activating a toolbutton to bring
up the associated popup menu. To work around this issue, just add a line before
the QtTesting recorded line to activate the toolbutton.

Change-Id: I14d17187755a9b0595b173e4fc50d8313dd45899
Merge topic '14573-deprecate-legacy-panels' into next

70090ec3 FIX: Fixed test using the new TextLocationWidget
4fbf55a6 Changes in FontPropertyWidget and TextLocationWidget
f6ce4c8c Removed legacy display panel widgets
bde38740 Use new display panel for spreadsheet view
ef023d4f Renamed pqTextWindowLocationWidget to pqTextLocationWidget
e0403c31 Reworked Text Source display panel
2b1e24f0 Deprecate legacy display panel for the Text Source