Use keyToInviteId from @mapeo/crypto

[EvanHahn]

This is a low-priority issue.

We have a function that converts a project key to a project invite ID:

comapeo-core/src/utils.js

Lines 129 to 138 in e153b44

	/**
	* Generate an invite ID from a project key
	* @param {Readonly<Buffer>} projectKey
	* @returns {Buffer}
	*/
	export function projectKeyToProjectInviteId(projectKey) {
	const result = Buffer.allocUnsafe(32)
	sodium.crypto_generichash(result, PROJECT_INVITE_ID_SALT, projectKey)
	return result
	}

This function also exists in @mapeo/crypto (see digidem/mapeo-crypto#26). We should delete our function and use the one from @mapeo/crypto instead.

Checklist:

• Release a new version of @mapeo/crypto
• Update to it in this repo
• Delete projectKeyToProjectInviteId from this repo, replace it with the keyToInviteId function from @mapeo/crypto