fix: wrap vim.fn.complete into pcall when adding to dot repeat

[geril07]

Problem:
There’s a window(resolve_timeout_ms) where you can do anything (like switch to Normal mode) between selecting a completion item and LSP resolving it. The problem is that vim.fn.complete throws an error outside of Insert mode. So if you type Tab -> Esc you can hit this problem if an LSP will take some time to resolve. Happens to me every day or two.

Solution: Wrap it into pcall and notify a user that dot repeat logic is failed. But I am not sure about the message format, maybe you can find a better one.

Before

before.mp4

After

after.mp4

But it opens up another problem. As you can see in the "after" demo, there's an incorrect t character left at the end of the completion. This happens because switching to Normal mode decreases the cursor's column position by 1, so the last character isn’t cleared.
Still, I think it’s better to deal with an extra character than with the original error.

I described more about this there #1491.

[Saghen]

In #2022, I decided to check if the mode was not insert, and ignore the dot-repeat call if so, without a warning message. I also included some other fixes for when the cursor moves while resolving. Could you give that PR a try and lmk what you think?