Add an optional flag to prevent opening a new browser tab

# Feature Request

## Motivation Behind Feature
In order to view file changes you need to stop and restart the browser server; when that is done Cordova opens a new tab on the active browser, even if a tab is already open for the Cordova project.
Having to close the currently open tab each time the server is rebooted gets annoying.

## Feature Description

Add a optional argument `--no-launch` which will start the server, but won't open a new browser window/tab.

Example:
`cordova run browser --no-launch`

## Alternatives or Workarounds

Using `cordova serve` achieves this functionality; however, serve currently has an issue with loading plugins:


(The plugins work as expected when using `cordova run browser` or `cordova run android`.)

Start at the `cordova run browser` entry point and trace how browser launch arguments are parsed and passed to the server. Check how `cordova serve` avoids opening a tab, then define completion as supporting `--no-launch` without changing the default launch behavior.

Written by the indexing model from the issue text.