Fix link tool interaction with other tools

[akulistus]

Problem:
Applying the link tool on top of other formatting may also remove other tools tags.

Issue:
#2890

Solution:
Refactor removeFakeBackground function so it would no longer remove text formatting.

[akulistus]

Don’t check the commits yet — I want to discuss the solution for the second part of the issue.

I discovered that the odd behavior is caused by this line:

editor.js/src/components/utils/popover/popover-inline.ts

Line 172 in 90d6dec

this.nestedPopoverTriggerItem?.handleClick();

When, for example, the bold tool is applied, the inline toolbar rerenders, this line executes, and the unlink method is called. That’s why the link formatting disappears.

Should we remove this line?

Additionally, I noticed that the inline toolbar constantly rerenders when the link element is selected. For some reason, this is caused by this line:

editor.js/src/components/inline-tools/inline-tool-link.ts

Line 205 in 90d6dec

this.nodes.input.value = hrefAttr !== 'null' ? hrefAttr : '';

I haven’t figured out exactly why, but changing from value to defaultValue resolves the issue.

[neSpecc]

this.nestedPopoverTriggerItem?.handleClick();

I don't think you should simply remove this line. Firstly, find out what this line is supposed to do. I don't remember it at the moment.