[FEATURE] `sortByBackendLayout` for CONTENT_JSON

[twoldanski]

New option allows to sort colPos by used backend layout on page

Example usage:

lib.content = CONTENT_JSON
lib.content {
    table = tt_content
    select {
        orderBy = sorting
    }
    sortByBackendLayout = 1
 }

Resolves: #745

[coveralls]

Pull Request Test Coverage Report for Build 9854250536

Details

• 0 of 10 (0.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.4%) to 65.779%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
Classes/ContentObject/JsonContentContentObject.php	0	10	0.0%
<!--	Total:	0	10	0.0%	-->

Files with Coverage Reduction	New Missed Lines	%
Classes/ContentObject/JsonContentContentObject.php	1	1.89%
<!--	Total:	1		-->

Totals
Change from base Build 9792843150:	-0.4%
Covered Lines:	988
Relevant Lines:	1502

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💛 - Coveralls