✨(react) add multi select

Adding this new variant makes necessary to reorganize the files to keep
a clear separations of concerns. As of now Select/index.tsx is just an
entrypoint to render either the mono or multi variant of the select.

packages/react/src/components/Forms/Select/mono.tsx

@@ -0,0 +1,54 @@
+import React, { PropsWithChildren } from "react";
+import { UseSelectStateChange } from "downshift";
+import { FieldProps } from ":/components/Forms/Field";
+import { optionToValue, SubProps } from ":/components/Forms/Select/mono-common";
+import { SelectMonoSearchable } from ":/components/Forms/Select/mono-searchable";
+import { SelectMonoSimple } from ":/components/Forms/Select/mono-simple";
+
+export interface Option {
+  value?: string;
+  label: string;
+  disabled?: boolean;
+}
+
+export type SelectProps = PropsWithChildren &
+  FieldProps & {
+    label: string;
+    hideLabel?: boolean;
+    options: Option[];
+    searchable?: boolean;
+    name?: string;
+    defaultValue?: string | number | string[];
+    value?: string | number | string[];
+    onChange?: (event: {
+      target: { value: string | number | undefined | string[] };
+    }) => void;
+    disabled?: boolean;
+    clearable?: boolean;
+    multi?: boolean;
+  };
+
+export const SelectMono = (props: SelectProps) => {
+  const defaultSelectedItem = props.defaultValue
+    ? props.options.find(
+        (option) => optionToValue(option) === props.defaultValue
+      )
+    : undefined;
+
+  const commonDownshiftProps: SubProps["downshiftProps"] = {
+    initialSelectedItem: defaultSelectedItem,
+    onSelectedItemChange: (e: UseSelectStateChange<Option>) => {
+      props.onChange?.({
+        target: {
+          value: e.selectedItem ? optionToValue(e.selectedItem) : undefined,
+        },
+      });
+    },
+  };
+
+  return props.searchable ? (
+    <SelectMonoSearchable {...props} downshiftProps={commonDownshiftProps} />
+  ) : (
+    <SelectMonoSimple {...props} downshiftProps={commonDownshiftProps} />
+  );
+};