feat: get likes/followers/followings

[sripwoud]

Closes #16 #17 #18 Add new handlers on following routes:

handler	route	description
handleGetLikesByPost	/v1/post/:hash/likes	returns list of users who liked a post
handleGetUserFollowers	/v1/:user/followers	returns list of followers a given user has
handleGetUserFollowings	/v1/:user/followings	return list of users of given user follows

Test

• unit tests: npm run test:some http

• example of manual requests:

  • likes:

    curl -X GET --location "http://localhost:3000/v1/post/0xC7E20724c409d9E8e3181a559F4c529B17dc1Bd7%2Fb298e95069867db8d2f5152d50f91029fbba01225f557bc180895f450d47bc6c/likes"

  • followers:

    curl -X GET --location "http://localhost:3000/v1/0xd44a82dD160217d46D754a03C8f841edF06EBE3c/followers"

  • followings:

    curl -X GET --location "http://localhost:3000/v1/0xC7E20724c409d9E8e3181a559F4c529B17dc1Bd7/followings"