Remove unnecessary imports on save not working

[snebjorn]

Issue Description

According to OmniSharp/omnisharp-roslyn#1581 then codeActionsOnSave should be able to fix issues on save.

"editor.codeActionsOnSave": {
  "source.fixAll.csharp": true
}

But I can't get it to remove unnecessary imports on save.
I can however run the fixes manually via the command palette.

I've included the OmniSharp log for running these manually.
Also why is there two for removing unused imports?
And shouldn't the CS8019 be IDE0005?

I have the following settings:

"[csharp]": {
  "editor.codeActionsOnSave": {
    "source.fixAll.csharp": true
  }
},
"omnisharp.enableEditorConfigSupport": true,
"omnisharp.enableRoslynAnalyzers": true,
"omnisharp.organizeImportsOnFormat": true

organizeImportsOnFormat does work, so something is working :)

Steps to Reproduce

Add an unused import statement, like using System.Buffers;. Then save.

Expected Behavior

using System.Buffers; should be removed.

Actual Behavior

using System.Buffers; isn't removed.

Logs

OmniSharp log

[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.RunFixAllCodeActionService Fixing CS8019. [info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.RunFixAllCodeActionService Fixing RemoveUnnecessaryImportsFixable.

C# log

Post the output from Output-->C# here

Environment information

VSCode version: 1.53.2
C# Extension: 1.23.9

Dotnet Information

.NET SDK (reflecting any global.json): Version: 5.0.101 Commit: d05174dc5a

Runtime Environment:
OS Name: Windows
OS Version: 10.0.19041
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\5.0.101\

Host (useful for support):
Version: 5.0.1
Commit: b02e13abab

.NET SDKs installed:
2.2.401 [C:\Program Files\dotnet\sdk]
3.1.404 [C:\Program Files\dotnet\sdk]
5.0.101 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
Angular-BeastCode	Mikael	10.0.3
angular-console	nrwl	16.0.2
angular-schematics	cyrilletuzi	4.10.1
angular-spectator-snippets	NetanelBasal	0.0.2
auto-barrel	mikehanson	1.9.0
better-align	wwm	1.1.6
better-comments	aaron-bond	2.1.0
bracket-pair-colorizer-2	CoenraadS	0.2.0
code-spell-checker	streetsidesoftware	1.10.2
csharp	ms-dotnettools	1.23.9
debugger-for-chrome	msjsdiag	4.12.12
docomment	k--kato	0.1.20
dotnet-interactive-vscode	ms-dotnettools	1.0.211402
dotnet-test-explorer	formulahendry	0.7.5
EditorConfig	EditorConfig	0.16.4
github-actions	formulahendry	0.0.1
gitlens	eamodio	11.2.1
jbockle-format-files	jbockle	3.0.0
markdown-all-in-one	yzhang	3.4.0
markdown-mermaid	bierner	1.9.2
mermaid-markdown-syntax-highlighting	bpruitt-goddard	1.2.0
ng-template	Angular	11.2.0
ng-zorro-vscode	cipchk	11.1.1
openapi-designer	philosowaffle	0.3.0
prettier-vscode	esbenp	5.9.2
sort-js-object-keys	zengxingxin	1.0.6
user-secrets	adrianwilczynski	2.0.1
vscode-dotnet-runtime	ms-dotnettools	1.0.0
vscode-drawio	hediet	1.3.0
vscode-eslint	dbaeumer	2.1.14
vscode-icons	vscode-icons-team	11.1.0
vscode-openapi	42Crunch	3.10.0
vscode-pull-request-github	GitHub	0.23.1
vscode-sql-formatter	adpyke	1.4.4
vscode-stylelint	stylelint	0.86.0
vscode-typescript-tslint-plugin	ms-vscode	1.3.3
vscode-versionlens	pflannery	1.0.9
vscode-yaml	redhat	0.15.0
vscodeintellicode	VisualStudioExptTeam	1.2.11
vsliveshare	ms-vsliveshare	1.0.3629
xml	DotJoshJohnson	2.5.1