internal/lsp: add titles to `go mod tidy` and update go.sum fixes
internal/lsp: add titles to `go mod tidy` and update go.sum fixes

These were missing titles, which was showing up empty for users in the
VS Code UI and leading people not to trust the fixes.

Also did a find references on SuggestedFix to confirm that we always
set the title in other cases.

Fixes golang/go#43234

Change-Id: I8d0f272c383a2e1a364aefcec6650988d18d4fb4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/278778
Trust: Rebecca Stambler <d7cf11e5f299d88ea8348366a9fc4f7c335c3afa@golang.org>
Run-TryBot: Rebecca Stambler <d7cf11e5f299d88ea8348366a9fc4f7c335c3afa@golang.org>
gopls-CI: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools