Collect regions to change as markers, then edit

Collect regions to change as markers, then edit

* eglot.el (eglot--lsp-position-to-point): Accept MARKER optional
arg.
(eglot--range-region): Accept MARKERS optional arg. Return a list.
(eglot--server-textDocument/publishDiagnostics)
(eglot--hover-info, eglot-eldoc-function): eglot--range-region
returns a list, not a cons.
(eglot--apply-text-edits): First collect regions as markers, then
edit.

GitHub-reference: close https://github.com/joaotavora/eglot/issues/4