feat(lsp): fallback to code-action command on resolve failure (#25464)

The haskell-language-server supports resolve only for a subset of code
actions. For many code actions trying to resolve the `edit` property
results in an error, but the unresolved action already contains a
command that can be executed without issue.

The protocol specification is unfortunately a bit vague about this,
and what the haskell-language-server does seems to be valid.

Example:

    newtype Dummy = Dummy Int
    instance Num Dummy where

Triggering code actions on "Num Dummy" and choosing "Add placeholders
for all missing methods" resulted in:

    -32601: No plugin enabled for SMethod_CodeActionResolve, potentially available: explicit-fields, importLens, hlint, overloaded-record-dot

With this change it will insert the missing methods:

    instance Num Dummy where
      (+) = _
      (-) = _
      (*) = _
      negate = _
      abs = _
      signum = _
      fromInteger = _

0 files changed, 0 insertions, 0 deletions