Eglot: fix textDocument/onTypeFormatting for 'newline' command

Eglot: fix textDocument/onTypeFormatting for 'newline' command

In the newline command, last-input-event is 13 (carriage return), but
most, if not all, language servers that support
documentOnTypeFormattingProvider expect 10 (linefeed) to be the
trigger, so convert 13 to 10 for the purposes of the
textDocument/onTypeFormatting request.

Also make this common edit silent in the mode-line/messages.

* lisp/progmodes/eglot.el (eglot--post-self-insert-hook): Convert
linefeed to carriage return.
(eglot-format): Pass SILENT to eglot--apply-text-edits.
(eglot--apply-text-edits): Take new optional SILENT arg.

* etc/EGLOT-NEWS: Mention change