#481 replaced SourceKit placeholders (like `<#code#>`) by LSP snippets for code actions, which are used to represent SourceKit refactoring and diagnostic Fix-Its. But LSP snippets are only supported for code completion, not for code actions. This results in LSP snippets like ${1:code} being inserted into the editor.
Instead of replacing SourceKit placeholders by LSP placeholders, we should just remove them altogether from the code action response.
rdar://92447079 [#488]
We will be able to split the LSP modules off later. These LSP modules
will provide the ability to write custom LSP servers and clients in
Swift. The sourcekit-lsp repository will build on top of this new
package to provide an LSP implementation that creates a language server
for Swift and C-based-languages.