Implement IBC profiles feature

[dadamu]

Description

This PR implement #192, creating cross-chain link by IBC protocol and inter-chain link by message.

IBC profiles module features:

• Create link struct on destination chain after relaying successfully
• Support create-ibc-link method to create a link by one key
• Provide create-ibc-connection method to create a link by two private keys used on target chain
• Include integration test, which checks the final statement after sending ibc profiles transactions

IBC feature in profiles module:

• Support cross-chain link creation service by receiving ibc-profiles packet from other chain
• Offer inter-chain link creation service
• Provide link storage in the database and Profile
• Allow unlink action to delete the link

Checklist

• Targeted PR against correct branch.
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Wrote unit tests.
• Wrote integration tests (simulation & CLI).
• Updated the documentation.
• Added an entry to the CHANGELOG.md file.
• Re-reviewed Files changed in the Github PR explorer.

[RiccardoM]

@dadamu If you think it would be better, I guess we can use Bech32 without any problem. I used the hex representation to make it chain-independent, but if we provide the ChainConfig object then it should be the same to use the Bech32 format instead.

Also, I would avoid putting the SourceAddress field inside a Link object. Since links will be present inside a Profile, it would be redundant to put a SourceAddress inside each link. This value would be identical to the profile address, and so it can be easily removed.

[dadamu]

@RiccardoM I got it, the cross-chain and inter-chain links are associated with Profile directly, not account. So desmos address is not needed in Link object. Thanks!

[RiccardoM]

Hey @dadamu, since this PR got quite big (more than 100 files to be checked), I think we should split it into multiple ones, each one with its review process.

To do this, what I would ask you to do is the following:

1. Create a new branch named paul/ibc-links starting from the current master branch.
2. Using that branch, create multiple consecutive PRs each one implementing one small change:
   1. The addition of Proto files
   2. The logic behind storing the links
   3. Tests
   4. Documentation

At each PR me and @bragaz will review it and once everything is done, merge it into the destination branch.

The overall process will be the following:

1. Fork master and create paul/ibc-links.
2. Put inside the paul/ibc-links the updated Proto files.
3. Open a new PR and ask me and @bragaz the review.
4. Once the review is approved and merged, add to the paul/ibc-links branch the logic to store the links.
5. Open a new PR and ask me and @bragaz the review.
6. Once the review is approved and merged, add to the paul/ibc-links branch the tests.
7. Open a new PR and ask me and @bragaz the review.
8. Once the review is approved and merged, add to the paul/ibc-links branch the documentation.
9. Open a new PR and ask me and @bragaz the review.

Ideally, all the PRs should be made towards a new branch called paul/ibc-profiles that will have all the changes. Finally, we will create a paul/ibc-profiles -> master PR and merge everything when it's all clear and finalized.

This way we will be able to review all the things faster and give you a more rapid feedback.

If all of this is clear, please start with creating the branches and close this PR.