Fix empty wildcard match on exports

[lauckhart]

This fixes a bug whereby a wildcard package.json export such as:

./foo/*/index.js

when matched against an import such as:

import "./foo/index.js";

would crash:

panic: runtime error: slice bounds out of range [50:49]

goroutine 31853 [running]:
github.com/microsoft/typescript-go/internal/modulespecifiers.tryGetModuleNameFromExportsOrImports(0x140001a8908, {0x1096fdd18, 0x14017902078}, {0x1400021c100, 0x3a}, {0x14000298310, 0x23}, {0x14000010fc0, 0xc}, {{0x58?, ...}, ...}, ...)
        github.com/microsoft/typescript-go/internal/modulespecifiers/specifiers.go:1215 +0xfe8
github.com/microsoft/typescript-go/internal/modulespecifiers.tryGetModuleNameFromPackageJsonImports-range1(...)
        github.com/microsoft/typescript-go/internal/modulespecifiers/specifiers.go:1000
github.com/microsoft/typescript-go/internal/modulespecifiers.tryGetModuleNameFromPackageJsonImports.(*OrderedMap[...]).Entries.func1(...)
        github.com/microsoft/typescript-go/internal/collections/ordered_map.go:175
github.com/microsoft/typescript-go/internal/modulespecifiers.tryGetModuleNameFromPackageJsonImports({0x1400021c100, 0x3a}, {0x140002dafc0?, 0x23?}, 0x140001a8908, {0x1096fdd18, 0x14017902078}, 0x63, 0x0)
        github.com/microsoft/typescript-go/internal/modulespecifiers/specifiers.go:990 +0x3e8
github.com/microsoft/typescript-go/internal/modulespecifiers.getLocalModuleSpecifier({0x1400021c100, 0x3a}, {0x0, {0x140002dafc0, 0x3d}, {0x140002dafc0, 0x2f}}, 0x140001a8908, {0x1096fdd18, 0x14017902078}, ...)
        github.com/microsoft/typescript-go/internal/modulespecifiers/specifiers.go:496 +0x8c4
...

[lauckhart]

@microsoft-github-policy-service agree

[jakebailey]

Is there a test you can make for this?

The fix seems obviously right, however. The original code looked more like:

            case MatchingMode.Pattern:
                const starPos = pathOrPattern.indexOf("*");
                const leadingSlice = pathOrPattern.slice(0, starPos);
                const trailingSlice = pathOrPattern.slice(starPos + 1);
                if (canTryTsExtension && startsWith(targetFilePath, leadingSlice, ignoreCase) && endsWith(targetFilePath, trailingSlice, ignoreCase)) {
                    const starReplacement = targetFilePath.slice(leadingSlice.length, targetFilePath.length - trailingSlice.length);
                    return { moduleFileToTry: replaceFirstStar(packageName, starReplacement) };
                }

Which we could technically replicate?