add destinationFeeBalance property in the response examples

[mmaurello]

Description

After the new changes deployed to the XCM-SDK, in which we return a new property destinationFeeBalance, we have to add the property in the example responses in the docs

The property destinationFeeBalance is useful when the asset paying for the fees in the destination chain is different from the asset being transferred and/or the asset paying for the fees in the source chain.

Example: sending WBTC from HydraDX to Moonbeam:

• asset transferred: WBTC
• pays for fees in HydraDX: HDX
• pays for fees in Moonbeam: GLMR

The property destinationFeeBalance helps controlling that the sender has enough GLMR in their HydraDX account.

Checklist

• If this requires translations for the moonbeam-docs-cn repo, I have created a ticket for the translations in Jira
• If pages have been moved around, I have created an additional PR in moonbeam-mkdocs to update redirects
• If pages have been moved around, I have run the move-pages.py script to move the pages and update the image paths on the chinese repo
  • After the script has been run, I have created an additional PR in moonbeam-docs-cn
• If images have been added, I have run the compress-images.py script to compress the images.
• If variables (in variables.yml) need to be updated (such as a name change), I have updated the moonbeam-docs-cn repo to use the new variables
• If this page requires a disclaimer, I have added one

Corresponding PRs

moonbeam-foundation/xcm-sdk#127

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.

[eshaben]

Thanks @mmaurello!! Merging this into a local branch to update the reference page