🏗️ [Core Feature]: XCM connections to other parachains

[KitHat]

What is the key feature we're aiming to implement?

We want to make the template ready for establishment of channels to these parachains:

• Snowbridge -- bridging tokens to Ethereum Mainnet
• HydraDX -- getting access to the secondary market of tokens
• AssetHub -- better SnowBridge support

More parachains may be added.
NB: no automatic channel establishment. We can only provide a guide with the proposals that they need to create to establish a channel between two parachains.

We are expecting it to be a guide showing the steps to establish a channel to any of those chains.

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[4meta5]

The foreign asset examples described in this issue description are blocked until we choose and implement a solution for #215 cc @ggonzalez94

[ggonzalez94]

It makes sense to ship #215 this as part of this milestone, especially if it is necessary to follow this guide and have foreign assets such as DOT. I've added it to the EVM milestone so we can prioritize it.

[4meta5]

Closed by #214