move the tailscale web client out of the cmd/tailscale/cli package, into
a new client/web package. The remaining cli/web.go file is still
responsible for parsing CLI flags and such, and then calls into
client/web. This will allow the web client to be hooked into from other
contexts (for example, from a tsnet server), and provide a dedicated
space to add more functionality to this client.
Updates tailscale/corp#13775
Signed-off-by: Will Norris <will@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
