CTRL-MMB double click no longer does Zoom to Objects in Eeschema

Description

Doing a double click with the middle mouse button while holding the CTRL key used to perform the "Zoom to Objects"function. Somewhere between commit d1322e7d (when this functionality was implemented) and now, this stopped working.

Steps to reproduce

1. Open a file in Eeschema
2. Zoom back
3. Double click the middle mouse button
4. hold the CTRL key and double click the middle mouse button
5. The view of the schematic doesn't change because "Zoom to Fit Objects" isn't getting called
6. Press CTRL-HOME (or click the icon in the toolbar)
7. The view should change with the schematic getting closer.

I'm submitting an MR to fix this right after submitting this issue

KiCad Version

Application: KiCad Schematic Editor

Version: (5.99.0-9618-g5ca7a2c457-dirty), debug build

Libraries:
	wxWidgets 3.1.4
	libcurl/7.71.1-DEV Schannel zlib/1.2.11

Platform: Windows 10 (build 19041), 64-bit edition, 64 bit, Little endian, wxMSW

Build Info:
	Date: Mar  4 2021 21:20:55
	wxWidgets: 3.1.4 (wchar_t,STL containers)
	Boost: 1.73.0
	Curl: 7.71.1-DEV
	Compiler: Visual C++ 1928 without C++ ABI

Build settings:
	KICAD_SCRIPTING=OFF
	KICAD_SCRIPTING_MODULES=OFF
	KICAD_SCRIPTING_PYTHON3=OFF
	KICAD_SCRIPTING_WXPYTHON=OFF
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
	KICAD_SCRIPTING_ACTION_MENU=OFF
	KICAD_SPICE=OFF
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE=OFF