(core) Enhance autocomplete and choice colors

Summary:
Choice columns can now add new choices directly
from the autocomplete menu. The autocomplete will
now highlight the first matching item, even if there are equally
ranked alternatives. No changes have been made to how the
autocomplete index is created, or how it scores items.

For choice and choice list columns, the filter menu will
now display values using their configured colors, similar to the
rest of the UI. Choice tokens throughout the UI now do a better
job of handling text overflow by showing an ellipsis whenever
there isn't enough space to show the full text of a choice.

Test Plan: Browser tests.

Reviewers: cyprien

Reviewed By: cyprien

Differential Revision: https://phab.getgrist.com/D2904

app/client/widgets/ChoiceToken.ts

@@ -0,0 +1,81 @@
+import {dom, DomContents, DomElementArg, styled} from "grainjs";
+import {colors, vars} from "app/client/ui2018/cssVars";
+
+export const DEFAULT_FILL_COLOR = colors.mediumGreyOpaque.value;
+export const DEFAULT_TEXT_COLOR = '#000000';
+
+export interface IChoiceTokenOptions {
+  fillColor?: string;
+  textColor?: string;
+}
+
+/**
+ * Creates a colored token representing a choice (e.g. Choice and Choice List values).
+ *
+ * Tokens are pill-shaped boxes that contain text, with custom fill and text
+ * colors. If colors are not specified, a gray fill with black text will be used.
+ *
+ * Additional styles and other DOM arguments can be passed in to customize the
+ * appearance and behavior of the token.
+ *
+ * @param {DomElementArg} label The text that will appear inside the token.
+ * @param {IChoiceTokenOptions} options Options for customizing the token appearance.
+ * @param {DOMElementArg[]} args Additional arguments to pass to the token.
+ * @returns {DomContents} A colored choice token.
+ */
+export function choiceToken(
+  label: DomElementArg,
+  {fillColor, textColor}: IChoiceTokenOptions,
+  ...args: DomElementArg[]
+): DomContents {
+  return cssChoiceToken(
+    label,
+    dom.style('background-color', fillColor ?? DEFAULT_FILL_COLOR),
+    dom.style('color', textColor ?? DEFAULT_TEXT_COLOR),
+    ...args
+  );
+}
+
+const cssChoiceToken = styled('div', `
+  display: inline-block;
+  padding: 1px 4px;
+  border-radius: 3px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: pre;
+`);
+
+const ADD_NEW_HEIGHT = '37px';
+
+export const cssChoiceACItem = styled('li', `
+  display: block;
+  font-family: ${vars.fontFamily};
+  white-space: pre;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  outline: none;
+  padding: var(--weaseljs-menu-item-padding, 8px 24px);
+  cursor: pointer;
+
+  &.selected {
+    background-color: ${colors.mediumGreyOpaque};
+    color: ${colors.dark};
+  }
+  &-with-new {
+    scroll-margin-bottom: ${ADD_NEW_HEIGHT};
+  }
+  &-new {
+    display: flex;
+    align-items: center;
+    color: ${colors.slate};
+    position: sticky;
+    bottom: 0px;
+    height: ${ADD_NEW_HEIGHT};
+    background-color: white;
+    border-top: 1px solid ${colors.mediumGreyOpaque};
+    scroll-margin-bottom: initial;
+  }
+  &-new.selected {
+    color: ${colors.lightGrey};
+  }
+`);