eescema: symbol browser load for a long time with large ODB library

Description

When adding components to eescema from a large ODB library (~10k entries) the time for the Symbol browser to show up is around 25 s, noticeably more than 5s in e.g. 8.0.2. I do not know if this is the case in v8.0.4 - and v8.0.3 had a bug where ODB libraries did not work (#18159 (closed)).

It does not seem to get any faster when directly opening the browser a second time - no cache speed-up.

The component browser opens up very quickly when I have a new project with no components. However, when I start to add components, each time the opening of the browser gets a bit slower. It does not seem to matter if the components I add are different from each other, or if I just copy one over and over. I can have a sheet with only one component copied 100x, and it takes about 20s to open, compared to less than one second on a clean project.

I found #16040 (closed) and it is still open, however this was not a problem in versions after that issue was posted.

Steps to reproduce

1. Have a large ODB library (~10k entries)
2. Open a design with 100+ components from the database in it
3. Add component to scematic

KiCad Version

Application: KiCad x86_64 on x86_64

Version: 8.0.5-dirty, release build

Libraries:
	wxWidgets 3.2.6
	FreeType 2.13.3
	HarfBuzz 9.0.0
	FontConfig 2.15.0
	libcurl/8.10.1 OpenSSL/3.3.2 zlib/1.3.1 libidn2/2.3.7 libpsl/0.21.5 nghttp2/1.63.0

Platform: Freedesktop SDK 24.08 (Flatpak runtime), 64 bit, Little endian, wxGTK, X11, gnome, x11

Build Info:
	Date: Sep 25 2024 17:28:07
	wxWidgets: 3.2.6 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.86.0
	OCC: 7.8.1
	Curl: 8.10.1
	ngspice: 43
	Compiler: GCC 14.2.0 with C++ ABI 1019

Build settings: