Adds support for using RichEdit 4.1, and sets the richedit control into
the correct mode for rendering arbitrary Unicode correctly. Removes
some unnecessary per-character refresh for improved performance.
Fixes: #12454
RichEdit allows text selection one character past end-of-string, so we
need to cater for that as well in passing text ranges to the character
grid.
Fixes: #12454
Fixes the release build where we do `nmake symbols` for developer/src,
which was failing on calls to these two sets of components. (In
windows/src, the build structure is different due to an additional layer
of folders, so we end up with no `nmake symbols` call on the common
components).
Note this also drags TextFileFormat.pas and KMDActionInterfaces.pas into
the package so have moved those into general and components folders
respectively, alongside KMDActions.pas and updated corresponding
project includes.
