Fix error messages when running tests

[mckenfra]

Before submitting your pull request

• I agree to license my code under the MPL 2.0 license.
• I rebased my work on top of the main branch.
• I ran npm test and all tests passed.
• I added test coverages if relevant.

Description

Fixes error messages shown when running npm run test due to:

1. window.matchMedia is unsupported by jsdom
2. Mocked document is unavailable when resolving promises in popup.js and pageAction.js where those promises are started but not awaited

Error messages example

> testpilot-containers@8.3.8 coverage
> nyc --reporter=html --reporter=text mocha test/**/*.test.js --timeout 60000

(node:66431) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)


  Assignment Reopen Feature
    set to 'Always open in' firefox-container-4
TypeError: window.matchMedia is not a function
    at Object.getTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:43:344)
    at Object.applyTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:43:793)
TypeError: window.matchMedia is not a function
    at Object.getTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:43:344)
    at Object.applyTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:43:793)
TypeError: window.matchMedia is not a function
    at Object.getTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:49:344)
    at Object.applyTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:49:793)
TypeError: window.matchMedia is not a function
    at Object.getTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:49:344)
    at Object.applyTheme (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:49:793)
      ✔ should open the page in the assigned container
TypeError: Cannot read properties of undefined (reading 'querySelector')
    at eval (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:81:281)
    at Array.forEach (<anonymous>)
    at Object.showPanel (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:81:115)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
TypeError: Cannot read properties of undefined (reading 'querySelector')
    at eval (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:81:281)
    at Array.forEach (<anonymous>)
    at Object.showPanel (eval at buildDom (multi-account-containers/node_modules/webextensions-jsdom/src/nyc.js:58:16), <anonymous>:81:115)
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)

Type of change

Select all that apply.

• Bug fix
• New feature
• Major change (fix or feature that would cause existing functionality to work differently than in the current version)