CSS line-height values should be unitless - editor.css

[ianbelanger]

As outlined in #44643, CSS line-height values should be unitless unless necessary to be defined as a specific pixel value. It was suggested that we break up 44643 by stylesheet in order to better track them.

This ticket covers much of wp-includes/css/editor.css, see patch notes below

Note: The patch was tested only on a Windows machine in Chrome, Firefox, IE11 and Edge. As per https://core.trac.wordpress.org/ticket/44643#comment:23 it should probably be tested on other OS's and supported browsers.

Patch Notes:

Unable to find selectors in the DOM. These may no longer exist in Core, but I am not 100% sure about that.

line 57 - .mce-window .mce-window-head .mce-title
line 70 - .mce-window .mce-window-head .mce-close, .mce-window-head .mce-close .mce-i-remove
line 228 - .mce-menu-has-icons i.mce-ico
line 242 - div.mce-tab
line 686 - .mce-window .mce-btn
line 848 - .mce-toolbar .mce-btn .mce-open

Would love to get confirmation of this from someone with intimate knowledge of Core TinyMCE.

[ianbelanger]

Updates patch with more precise line-height calculations

[SergeyBiryukov]

In 45477:

CSS Coding Standards: Use unitless values for line-height in wp-includes/css/editor.css.

Props ianbelanger, pbiron, afercia.
Fixes #46528. See #44643.