Updating "viewer_mps": fix "no_rectify_image" Aria Gen 1 bug and add flags for Rerun web ports

[KevinyWu]

Two changes to the viewer_mps function.

1) Fixing Issue #299

With version 2.0.0, when I run viewer_mps for an Aria Gen 1 recording with --no_rectify_image, I get:

NotImplementedError: Showing upright-rotated image without rectification is not currently supported.
Please use --no_rotate_image_upright and --no_rectify_image together.

However, --no_rotate_image_upright is no longer supported in 2.0.0:

viewer_mps: error: unrecognized arguments: --no_rotate_image_upright

2) Add flags for Rerun web ports

There is currently no option to modify the web and WebSocket ports that Rerun is served on in --web mode when using viewer_mps. The ability to set ports is useful to view multiple recordings simultaneously, or if the default ports are already used. By default --web_port and --ws_port are 0, which dynamically allocates an available port.

I have also updated the website documentation.