Inline edit fixes and improvements

[pgorod]

Description

This PR...

• makes inline edit use only one back-end request instead of two, sometimes three. This improved speed is quite welcome, not just to allow users to move faster, but also to prevent UX errors such as when people redo or undo an action accidentally because of a delay. If you've used inline edit with a not-so-fast server, you know what I mean...
• moves a couple of auxiliary functions from Home controller to inlineEditing.php
• adds the standard validations, as defined in vardefs, to inline editing: callback, range, isbefore, less, more, binarydep, comparison, in_array, verified. Adds a new one, isafter.
• makes inlineEditing.php customizable
• fixes a few minor bugs

Closes #8886
Closes #9818
Supersedes #8858
Supersedes #10240

Thanks to @gunnicom and @SinergiaCRM for their code or comments in those previous PR's, they were very useful to me in this work.

How To Test This

I suggest starting by adding this callback example that @gunnicom provided to the Opportunities vardefs, name field:

modules/Opportunities/vardefs.php

    'validation' => 
    array (
      'type' => 'callback',
      'callback' => 'function(formname,nameIndex){
                           var fieldvalue=$("#" + formname + " input[name=" + nameIndex + "]").val();
                           var returncode=true;
                           if(fieldvalue.trim()!=fieldvalue){
                               add_error_style(formname,nameIndex,"Space at the start or end of value not allowed " + nameIndex); 
                               returncode= false;
                           }
                           return returncode;
			}',
    ),

... then QR&R.

Now test with:

• random places throughout the app, doing inline edits
• number validation: test with Opportunities Probability (between 0 and 100)
• callback validation: test with Opportunities name adding spaces in the beginning or end
• int validation: test with Calls duration hours

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Final checklist

• My code follows the code style of this project found here.
• My change requires a change to the documentation.
• I have read the How to Contribute guidelines.

[pgorod]

Known Issue: there's an edge case that doesn't work so well: in 'isbefore' validations, typically used when there are date ranges involved (start + end dates), the validation is only in effect in one of the two fields. In normal Edit views, both fields will be validated, so it's enough for one of them to throw the error.

But in inline edit, if you inline-edit the other one, no validation will take place, even if two relative dates are out of order. To fix this we would need also a isafter filter, and set validations on both fields. I added the code for that new validation type, but I didn't go and check all the vardefs where isbefore is used. I don't think this is worth much trouble, if somebody really cares about this, they can update their vardefs.

Note that my PR doesn't introduce the problem, it was there before... I fix a lot of other things, though not this one. I provide means to facilitate fixing it, that's good enough for the time available to work on this... 👼