Integrate aUSD on Rococo

[5-mark]

Step 1: ORML xtokens

• Integrate ORML xtokens into parachain runtime #82

Step 2: HRMP Testing

• Schedule testing date with Greg in Telegram
• Designate a technical lead to conduct HRMP channel testing with Joey from Karura
• Conduct testing on scheduled date
• Joey to confirm once HRMP testing has been successfully completed

Step 3: On-chain execution

Motion to open the HRMP channels and register Karura tokens

• Karura council to submit motion to open the HRMP channel and your team would need to accept
• Reciprocate the HRMP channel request to open the channel between your network and Karura
• Karura accepted the HRMP channel request
• Register KAR, aUSD, LKSM on your network using [this](https://wiki.acala.network/integrate/integration-1/protocol-info#multilocation) token registration info

Test token transfers

• Conduct token transfers with registered tokens

Marketing

• Share an announcement on your social channels that HRMP channels have been opened between networks. [Here](https://twitter.com/KaruraNetwork/status/1499859297232211968) is an example of one we shared with our community.
  Karura social will retweet your announcement. Please indicate in Telegram when this has been posted.

[vayesy]

Created issue on Polkadot/Subport repo to reset Subzero chain and enable it in the slot rotation to produce blocks. Once our chain will be restarted on the Rococo, will continue with this ticket.

[vayesy]

Successfully tested transfers between Zero and Acala chains on Rococo env.
Checked with the following tokens: ZERO, GAME, aUSD.

[vayesy]

@5-mark @leyanikitova I'm not sure about marketing part of the ticket. Leaving this up to you.