Improve dialog layout and fix UI policy issues with all of the dialog
boxes in the common, 3D viewer, CvPcb, and Eeschema code paths.
Updated the use of component to symbol.
* Prevent power component warning from being shown when edit normal component
fields.
* Make text edit dialog size itself instead of using a fixed size.
* Improve the alignment and spacing in the text edit dialog.
* Refactor edit one field dialogs to use validators and transfer data to and
from window functions.
* Add code to DIALOG_SHIM to handle validation and transfer functions since
the base dialog class code is not called by EndQuasiModal().
* Add custom validator class for filtering field text control characters.
* Add new field validator to edit schematic component dialog field text
control.
* Add new field validator to edit fields in library editor dialog field
text control.
* Make a few LIB_PART member functions const.
* Replace all occurrences of the word "part" with "unit" when referring to
multiple unit components for improved consistency.
* Replace "shared by" with "common to" when referring to objects (lines, arcs,
pins, etc.) that are common to all units.
* Improve wording in library component properties dialog.