fix: keep unit aliases in imports-order autofix

[SahilRajputdotexe]

The imports-order autofix rebuilds every import statement, but it only knows two shapes: import { A } from 'path' and a bare import 'path'. An import with a unit alias falls into the second one, so --fix drops the alias:

import * as Utils from './libraries/Utils.sol';
import './Types.sol' as Types;

becomes

import "./libraries/Utils.sol";
import "./Types.sol";

and the fixed file no longer compiles.

This rebuilds those imports with their alias, in the form they were written. Both forms are added to the imports-order e2e fixture.

[vschernoff]

Approving. Verified by running it rather than only reading the diff.

The bug reproduces on develop — --fix drops the alias entirely:

before   import * as Utils from './libraries/Utils.sol';
after    import "./libraries/Utils.sol";

Both forms are preserved with this PR:

import * as Utils from "./libraries/Utils.sol";
import "./Types.sol" as Types;

The implementation is safe. I checked the parser output directly: whenever unitAlias is set, both unitAliasIdentifier and pathLiteral are present with ranges, so the range[0] comparison cannot throw — and it is guarded inside if (node.unitAlias) regardless. The comparison correctly distinguishes the two forms.

One thing to note, not a blocker and not caused by this PR: no-unused-import --fix produces import * as from "..." — invalid Solidity — on the same import shape. imports-order reports no violation on that file, so it is a different rule entirely. Filed as #806 so it is not assumed fixed by this.