add node v21 nightly to test ci pipeline

• add node v21 nightly to test ci pipeline
• send wide uri definitions to loader using loader worker
• encountered upstream error when attempting to add node v20 tests

detect async variant import.meta.resolve

• detect async import.meta.resolve and handle in a separate way
• remove un-necessary usage of await keyword in README example
• require node version less than 20.x

use Object.defineProperty to define mock properties

use Object.defineProperty to write mock definitions protected on inherited prototype chain, re #196

throw error when esmock.stricted is called with empty mock

• throw error when esmock.strictest is called with empty mock definition, @koshic @Swivelgames
• update jest and jest-light-runner packages at unit-tests, @koshic

usability, restore previous mock-defining behaviour

This release adds node v19 to the ci-test pipeline and restores the previous mock defining-behaviour where properties can be seen easily with something like console.log(mockimported). This "un-does" a previous MR from 3 days ago that left part of the definition in the prototype chain, where properties were less discoverable.

@mshima windows drive letter patch

resolve windows modules with correct drive letter using resolvewithplus patch from @mshima

added CONTRIBUTING.md

Adds a CONTRIBUTING.md and use the live module's default export in prototype of returned mock definition, to resolve class-instance mock related issue

support yarn PnP

This release makes esmock compatible with yarn PnP. To do this, esmock is published with no dependencies and is instead bundled with resolvewithplus. Changes for this release,

• Changes the package-exported file to esmock.js from esmockLoader.js, a clerical change to make the "main" esmock file more obvious,
• Embeds the resolvewithplus package inside esmock, so the published package will have no dependencies and will support yarn PnP, thanks @koshic
• Detects and uses import.meta.resolve, rather than resolvewithlus, when it is provided by the host environment. See flag --experimental-import-meta-resolve
• Detects the presence of esmock's loader by using the loader directly. Previously, esmock tested process args with a regexp like this /--(experimental-)?loader[=\s,"']*esmock/.test(process.argv). Directly using the loader is more precise and allows other scripts to wrap and use esmock in un-anticipated ways, credit @koshic

show full path at error message

show full path at error message, making it easier to identify an invalid path. Related #174

add "esmock.strictest"

This release adds esmock.strictest --a stricter version of esmock.strict which requires every module imported to the target module to be mocked,

• add support for esmock.strictest, a more-strict variant of esmock, per @gmahomarf
• use more-descriptive internal-variable "treeId", rather than "esmockKey"
• include .mjs files in eslint filter and lint-fix existing .mjs files