test: SSR E2E Test Scenarios (#17666)

[Zeyber]

No description provided.

[Platonn]

Let's allow for injecting extra Spartacus config chunk, by passing it via a special cookie.
We already have a mechanism for this (implemented in Spartacus TestConfigModule) and it's already used in our Cypress E2E tests. Let's just use it here as well.
The cookie name is cxConfigE2E and the Spartacus TestConfigModule reads it and injects
the config passed via the cookie into Spartacus global config.

Beloww a snippet of code to pass a the cxConfig as an extra cookie:
NOTE: btw. I've changed the signature of the function's argument from path:string to object {path:string, cxConfig?: Config}

Suggested change

	export async function sendRequest(path: string) {
	return new Promise((resolve, reject) => {
	const req = http.get({ ...REQUEST_OPTIONS, path }, (res: any) => {
	import { Config } from '@spartacus/core';
	/* ... */
	export async function sendRequest({
	path,
	cxConfig
	}: {
	path: string,
	cxConfig?: Config
	}) {
	return new Promise((resolve, reject) => {
	const req = http.get({
	...REQUEST_OPTIONS,
	path,
	headers: {
	Cookie: buildCxConfigCookie(cxConfig)
	}, (res: any) => {

and let's add a function:

/**
  * Builds a cookie string with key 'cxConfigE2E' and the given `cxConfig`
  * object as a value that is stringified and URI-encoded.
  *
  * Note: `TestConfigModule` of Spartacus will read this cookie
  * and inject the passed config chunk into Spartacus global config.
  */
function buildCxConfigE2ECookie(cxConfig?: object): string {
  if(!cxConfig) {
    return {};
  }
  const cookieKey = 'cxConfigE2E';
  const cookieValue = encodeURIComponent(JSON.stringify(cxConfig));
  return `${cookieKey}=${cookieValue}`
}