gopls/internal/hooks: add Staticcheck's quickfix category of checks

Staticcheck's new quickfix category contains optional code
refactorings, such as turning a chain of if/else-if into a switch
statement, or simplifying boolean expressions.

These checks produce diagnostics with the "hint" or "information"
severities. Most use "hint", which produces a subtle hint in VSCode's
UI that a refactoring is available. "information" produces a blue
underline and is only used for those checks that have a very high
likelyhood of improving code readability.

Change-Id: I8f5b4eca67eb6b4e45c17510459d83eb673384e3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/322492
Trust: Dominik Honnef <dominik@honnef.co>
Run-TryBot: Dominik Honnef <dominik@honnef.co>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>

gopls/internal/hooks/analysis.go

@@ -11,6 +11,7 @@ import (
 	"golang.org/x/tools/internal/lsp/protocol"
 	"golang.org/x/tools/internal/lsp/source"
 	"honnef.co/go/tools/analysis/lint"
+	"honnef.co/go/tools/quickfix"
 	"honnef.co/go/tools/simple"
 	"honnef.co/go/tools/staticcheck"
 	"honnef.co/go/tools/stylecheck"
@@ -55,4 +56,5 @@ func updateAnalyzers(options *source.Options) {
 		"SA5011": {},
 	})
 	add(stylecheck.Analyzers, nil)
+	add(quickfix.Analyzers, nil)
 }