Problem:
With some LSP servers, `vim.lsp.buf.signature_help` (CTRL-s in insert-mode)
highlights the first parameter regardless of the current cursor position.
- On some lsps the `textDocument/signatureHelp` response only includes the
`activeParameter` field on the `lsp.SignatureHelp` object.
```lua
{
{
result = {
activeParameter = 2,
signatures = {
{
documentation = {
kind = "markdown",
value = ""
},
label = "getBuyers(ctx context.Context, orderDB boil.ContextExecutor, supplierID string) ([]*BuyerWithLocation, error)",
parameters = {
{
label = "ctx context.Context"
},
{
label = "orderDB boil.ContextExecutor"
},
{
label = "supplierID string"
}
}
}
}
}
}
}
```
Solution:
Ensure we retain this information before showing the signature information.
Closes#32381