feat: File attachments (#3031)

* stash

* refactor, working in non-collab + collab editor

* attachment styling

* Avoid crypto require in browser

* AttachmentIcon, handling unknown types

* Do not allow attachment creation for file sizes over limit

* Allow image as file attachment

* Upload placeholder styling

* lint

* Refactor: Do not use placeholder for file attachmentuploads

* Add loading spinner

* fix: Extra paragraphs around attachments on insert

* Bump editor

* fix build error

* Remove attachment placeholder when upload fails

* Remove unused styles

* fix: Attachments on shared pages

* Merge fixes

shared/editor/components/DisabledEmbed.tsx

@@ -0,0 +1,20 @@
+import { OpenIcon } from "outline-icons";
+import * as React from "react";
+import { DefaultTheme, ThemeProps } from "styled-components";
+import { EmbedProps as Props } from "../embeds";
+import Widget from "./Widget";
+
+export default function DisabledEmbed(props: Props & ThemeProps<DefaultTheme>) {
+  return (
+    <Widget
+      title={props.embed.title}
+      href={props.attrs.href}
+      icon={props.embed.icon(undefined)}
+      context={props.attrs.href.replace(/^https?:\/\//, "")}
+      isSelected={props.isSelected}
+      theme={props.theme}
+    >
+      <OpenIcon color="currentColor" size={20} />
+    </Widget>
+  );
+}