Implement MembershipManager contract

[halink0803]

Here is the create new membership contract workflow.

Create Membership

struct Membership {
        string name,
        uint256 duration,
        uint256 maxSupply,
        uint256 price
}

The membership contract should be able to

• Create new Membership.
• keep a record of membership sales.
• Query membership sales

Required

• SoulBoundNFTs Contract

• EthTransfer Contract