"Delete All Markers" in ERC/DRC asks about deleting excluded markers and has an ambigous checkbox

Description

There is a thread on the KiCad forum where a user asked about this dialog. It pop-ups if there are exclusions in ERC or DRC. It brought several questions up in the thread that seem worth considering:

1. Why does this get asked anyway?
2. What does the checkbox do?
3. What happens if you check the box then hit cancel?
4. What happens if you just hit cancel? Do all the other markers get deleted but not exclusions?

The consensus appears to be this dialog does not make sense to users.

"Delete All Markers" should ... delete all the markers. Yet, this dialog only happens if there are exclusions.

To add to the mystery, why does this particular dialog have "Delete Exclusions" associated with it?

It appears that a commit in #4953 (closed) has added the dialog, but it is not clear (to me) why.

Steps to reproduce

1. Open a PCB
2. Run DRC and get warnings and errors
3. click Delete All Markers

All markers are deleted, as expected.

1. Run DRC and get warnings and errors
2. Exclude one report
3. click 'Delete All Markers'

A mysterious dialog appears.

KiCad Version

(Applies to anything after 6.)

Application: KiCad PCB Editor x64 on x64

Version: 7.0.10, release build

Libraries:
	wxWidgets 3.2.4
	FreeType 2.12.1
	HarfBuzz 8.2.1
	FontConfig 2.14.2
	libcurl/8.4.0-DEV Schannel zlib/1.3

Platform: Windows 10 (build 19045), 64-bit edition, 64 bit, Little endian, wxMSW

Build Info:
	Date: Dec 28 2023 21:18:15
	wxWidgets: 3.2.4 (wchar_t,wx containers)
	Boost: 1.83.0
	OCC: 7.7.1
	Curl: 8.4.0-DEV
	ngspice: 41
	Compiler: Visual C++ 1936 without C++ ABI

Build settings:
	KICAD_SPICE=ON