Shortcut LVL can discart lower level too brutally

[Goaman]

If you have a shortcut that match with the keymap in a specific LVL (e.g. USER (LVL1)), it stop rerturning the match for a previous LVL (e.g. DEFAULT (LVL0)).

Because of the following logic in Keymap.ts:

if (matchingCommands.length) {
    // Matches were found at this level so do not look lower.
    break;
}

This mechanism was put in place for being able to override a shortcut in a LVL higher previous lvl that could match with the shortcut.

However, if we create a selector that match anything in the user LVL2:

A user defining a shortcut:

{
  pattern: 'TAB',
  selector: [() => true],
  commandId: 'openLinkDialog',
}

Any shortuct TAB in user space will be discarted.

Thus making the tab shortcut for list not working.

We need to rethink to not discart the all the shortcut of a lower level.

[Gorash]

eg:

If create a shortcut custom Delete USER level who match with the DIV container, the Delete in list item of UL to outdent does not work anymore.

<div>abc<div>
<ul>
 <li class="li_1">
   <ul><li></br></li></ul>
 </li>
</ul>
<div>
 <ul>
   <li class="li_2">
     <ul><li></br></li></ul>
   </li>
 </ul>
</div>

Delete in DIV trigger custom
Delete in LI.li_1 must trigger outdent (broken)
Delete in LI.li_2 must trigger custom