Changes related to polkadot-sdk v.1.7.2 and XCM v4

[eshaben]

Description

This PR updates the docs for the changes made to support the polkadot-sdk v.1.7.2 release, which includes XCM v4. I also took time to update the MRL docs and do a general cleanup of snippets.

Important things to note:

• With XCM v4, concrete/abstract has been removed
• With X1 junctions, you have to wrap the value in an array
• There were some internal name changes that drop the multi prefix, so multilocation > location, multiasset > asset

✍️ I have not changed our widespread use of multilocation to location

⚠️ I deleted some old snippets and updated the names of others for consistency. This will break the examples on the Chinese docs site.

Checklist

• I have added a label to this PR 🏷️
• I have run my changes through Grammarly
• If this requires translations for the moonbeam-docs-cn repo, I have created a ticket for the translations in Jira

After Translation Requirements

• Will need to create PR in moonbeam-docs repo to remove images
• Will need to create PR in moonbeam-docs repo to remove variables
• Will need to create PR in moonbeam-mkdocs repo to add redirects for Chinese site
• No additional PRs are required after the translations are done

Items to be Updated

Please list any of the items that will need to be added or deleted after the translations are done here.

[albertov19]

LGTM - @themacexpert please can you confirm that the tutorials are working?

@eshaben did you try the updated tutorials?

[eshaben]

I went through each of the code snippets and made sure that all of the examples were properly formatted and generated the correct encoded calldata. I did not go through the tutorials from top to bottom.

[eshaben]

@themacexpert thanks so much for checking these and switching to terminal snippets!!!

[eshaben]

Updated the alphanet weights for the x-tokens pages. I'll do a separate PR to update polkadot and kusama

[themacexpert]

I tried out snippets with the new weights, working well!
Just found a few broken links is all. I think with the EIP-20 link there are multiple instances of that on the docs site so would be great to get them all.

[themacexpert]

Line 59 parachain-embedded-specs link is broken

[themacexpert]

Line 402 https://eips.ethereum.org/EIPS/eip-20/ Link is broken

[eshaben]

@themacexpert it's related to the changes that just went through with the links. I just did a hard reset on all the links so these should be fixed in #922 and once that PR gets published, I'll run a scan to make sure that I clean up and remaining links that result in 404s