Hierarchy navigator positioning not remembered

Description

ee0f93ed did fix the hierarchy pane disappearing (#12087 (closed), thanks!). However, it also rearranged the UI elements so the panel is to the left of the toolbar. It's a really minor thing but I do find it annoying, so I tried moving the panel back where it was, which works - but then this is not remembered if I close and reopen.

Steps to reproduce

1. Drag the hierarchy pane to the right of the left toolbar
2. Restart KiCad
3. Hierarchy pane is back on the far left.

KiCad Version

Application: KiCad Schematic Editor

Version: (6.99.0-2642-g3245aec5b5), release build

Libraries:
	wxWidgets 3.1.5
	FreeType 2.12.1
	HarfBuzz 5.0.1
	FontConfig 2.14.0
	libcurl/7.79.1 SecureTransport (LibreSSL/3.3.6) zlib/1.2.11 nghttp2/1.45.1

Platform: macOS Version 12.5 (Build 21G72), 64 bit, Little endian, wxMac

Build Info:
	Date: Jul 29 2022 14:34:14
	wxWidgets: 3.1.5 (wchar_t,wx containers)
	Boost: 1.79.0
	OCC: 7.6.2
	Curl: 7.64.1
	ngspice: 35
	Compiler: Clang 12.0.0 with C++ ABI 1002

Build settings:
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON