add tests ensuring import.meta.url paths succeed windows linux

[iambumblehead]

iambumblehead/esmock#114

[iambumblehead]

const pathModuleFull = resolvewith(modulePath, calleePath)

values from failing esmock test,

 {
  modulePath: 'D:\\a\\esmock\\esmock\\tests\\tests-source-map\\dist\\index.js',
  calleePath: '\\a\\esmock\\esmock\\tests\\tests-source-map\\src\\__tests__\\index.test.ts',
  pathModuleFull: null
}

values from passing test

{
  modulePath: '../index.js',
  calleePath: '/a/esmock/esmock/tests/tests-source-map/dist/__tests__/index.test.js',
  pathModuleFull: 'D:\\a\\esmock\\esmock\\tests\\tests-source-map\\dist\\index.js'
}

[iambumblehead]

maybe check for this pattern '\' eg, /\\\\/.test(path)

[iambumblehead]

this was resolved with #31