scripts/check_license_headers: enforce license on ts/tsx files

Enforcing inclusion of our OSS license at the top of .ts and .tsx
files. Also updates any relevant files in the repo that were
previously missing the license comment. An additional `@license`
comment is added to client/web/src/index.tsx to preserve the
license in generated Javascript.

Updates #10261

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>

client/web/src/ui/badge.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React, { HTMLAttributes } from "react"
 

client/web/src/ui/collapsible.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import * as Primitive from "@radix-ui/react-collapsible"
 import React, { useState } from "react"
 import { ReactComponent as ChevronDown } from "src/assets/icons/chevron-down.svg"

client/web/src/ui/input.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React, { InputHTMLAttributes } from "react"
 

client/web/src/ui/popover.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import * as PopoverPrimitive from "@radix-ui/react-popover"
 import cx from "classnames"
 import React, { ReactNode } from "react"

client/web/src/ui/profile-pic.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React from "react"
 

client/web/src/ui/search-input.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React, { forwardRef, InputHTMLAttributes } from "react"
 import { ReactComponent as Search } from "src/assets/icons/search.svg"

client/web/src/ui/spinner.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React, { HTMLAttributes } from "react"
 

client/web/src/ui/toggle.tsx

@@ -1,3 +1,6 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
 import cx from "classnames"
 import React, { ChangeEvent } from "react"