RPL Viewer Prep [2]: Move RplBlock/FunctionDlg menus from UI into C++
Bug Number: n/a
Release notes (y/n): no
For Release Nums: 7.2

This is the 2nd of two commits to prepare to deploy the full implementation 
of the RplBlockDlg and RplFunctionDlg as "tabs" in a new RplViewerDlg.

THIS commit delegates the FULL implementation of RplBlockDlg and 
RplFunctionDlg to these two panel (QFrame) classes, which can now
be deployed anywhere we'd like (e.g. in a RplViewerDlg class):

  (1) class RplBlockDlgFrame    : public QFrame, public RplDlgFrameBase
  (2) class RplFunctionDlgFrame : public QFrame, public RplDlgFrameBase

The orginal RplBlockDlg and RplFunctionDlg classes no longer have any 
application-related code.  They delegate ALL virtual overrides from RplBaseDlg 
and a couple public methods to the new panel (QFrame) classes.  For what it's 
worth, their original Qt Designer UI files were retained, but are virtually 
empty -- all they have is a container widget in which instances of the new 
frame classes are deployed.

See the original RplBlockDlg and RplFunctionDlg constructors.  They 
demonstrate calls the panel classes to INSTALL THEIR MENU on the dialog's 
(QMainWindow's) menubar.  This operation can be performed dynamically, e.g. 
by the new RPL Viewer dialog when a different RPL Block or RPL Function tab 
is selected.

The new RplViewerDlg (just conceptual now) should be able to maintain these 
frame instances as just generic 'RplDlgFrameBase' instances (as TABS), once 
instantiated.  (Though, I'm noticing that we'd need to make the public 
'installMenuBar' method virtual from that base class).

The 'diff' used by GitExtensions IS recognizing the new panel classes as 
copies of the original -- so the history of that code should be retained.
I'm crossing my fingers that this will be retained during the commit.  When 
it comes time to merge this code to the master (RW 7.2) branch, I'd like to 
individually place this and the prior commit on that branch, to hopefully 
retain the history of this code.

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