Feature request: Add helpers for specifying method argument

[Thegaram]

In some contracts, constructor or method parameters represent concepts like:

• Amount in Drip,
• Date in epoch time,
• Duration in seconds.

It would be nice if Conflux Studio could provide common conversion utilities, e.g.

• CFX to Drip: When I type 10, it converts it into 10 * 1e18 (uint256)
• Date to epoch time: When I choose 2020/09/15, it converts it into epoch time (uint256)
• Duration to seconds: When I input 1 year, it converts it into 365 * 24 * 3600 (uint256)

Example:

pragma solidity ^0.5.0;

contract Vault {
    address owner;
    uint256 unlock_after;

    constructor(uint256 duration_s) public payable {
        owner = msg.sender;
        unlock_after = now + duration_s;
    }

    function withdraw() public {
        require(msg.sender == owner);
        require(now >= unlock_after);
        msg.sender.transfer(address(this).balance);
    }
}

When I try to deploy, I see this:

I think it would be great UX to allow specifying raw input but also provide some utility converters at fields like this (maybe through a dropdown menu).

[qftgtr]

In v0.4.0 you can select from saved keypairs for type address. We will add more in future versions.