Fixing and improving createMenuItem

[muhme]

Problems found while documenting and testing the functionality:

1. The custom command createMenuItem, working in Joomla 4, fails in Joomla 5 with:

AssertionError: Timed out retrying after 4000ms: Expected to find element: `.controls > .input-group > .btn`, but never found it.

2. The language setting was not implemented

This PR makes createMenuItem

• Working for the default and all active Joomla branches and
• Implements setting the language.

Additional

• Improving method comment (PR will follow for all methods)
• Directly defining the function
• Standardisation of the coding style by omitting single semicolons

Tests

This PR is extensively tested with test.cy.js based on joomla-cpress 1.1.0 plus #29:

• Intel macOS 14.5 Sonoma native with Joomla 4.4-dev
• Intel macOS 14.5 Sonoma docker-based with Joomla 4.4-dev, 5.1-dev, 5.2-dev and 6.0-dev
• Windows 11 Pro Laragon with Joomla 5.1-dev
• Windows 11 Pro WSL 2 docker-based with Joomla 4.4-dev, 5.1-dev, 5.2-dev and 6.0-dev

Sample test output:

  Running:  test.cy.js                                                                      (1 of 1)
  Test createMenuItem
    ✓ have fresh start with installJoomla (23138ms)
    ✓ can create with minimum arguments - 1st (4877ms)
    ✓ can create with explicit set menu and (unused) language - 2nd (4660ms)
    ✓ can create in different menu - 3rd (5762ms)
    ✓ change to multilingual website and install second language ja-JP (10877ms)
    ✓ still can create with minimum arguments - 4th (5467ms)
    ✓ can create with explicit set menu and using language ja-JP - 第5 (4698ms)
    ✓ can create with third language uk-UA - 6-й (13427ms)

Created menu items are:

👉 This custom command is actual not used in Joomla System Tests.

[laoneo]

Thanks!