Add import alias support for Cadence contracts

[chasefleming]

This adds import alias support to Flowkit, allowing contracts to be imported under different names while referencing a canonical contract's source code.

Example

flow.json Configuration

{
  "contracts": {
    "FUSD": {
      "source": "./contracts/FUSD.cdc",
      "aliases": {
        "testnet": "0x9a0766d93b6608b7",
        "mainnet": "0x3c5959b568896393"
      }
    },
    "FUSD1": {
      "source": "./contracts/FUSD.cdc",
      "aliases": {
        "testnet": "0xe223d8a629e49c68",
        "mainnet": "0x8d0e87b65159ae63"
      },
      "canonical": "FUSD"
    },
    "FUSD2": {
      "source": "./contracts/FUSD.cdc", 
      "aliases": {
        "testnet": "0x0f9df91c9121c460",
        "mainnet": "0x754a90d51a1c8e1b"
      },
      "canonical": "FUSD"
    }
  }
}

Import Syntax Conversion

Before Processing:

import "FUSD"
import "FUSD1" 
import "FUSD2"

After Processing by Flowkit:

import FUSD from 0x9a0766d93b6608b7
import FUSD as FUSD1 from 0xe223d8a629e49c68
import FUSD as FUSD2 from 0x0f9df91c9121c460

The canonical contract (FUSD) uses regular import syntax, while alias contracts (FUSD1, FUSD2) use the import X as Y syntax, allowing multiple imports of the same contract with different names.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 92.50000% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
project/imports.go	78.94%	3 Missing and 1 partial ⚠️
state.go	66.66%	1 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

[jribbink]

nit: do we need this? feels like practically someone would just use state.Contracts()[idx].Canoncal or equivalent

will it actually be needed for import replacement?