Merge branch 'cs/#6699-zend-dom-psr-2-compat'

Close #6699
added zendframework/zendxml into require at Zend\Json's composer.json
move zendxml to suggest and mark to Json::fromXml() as @deprecated
update comment on suggest
fix Zend\Db\Adapter\Platform\PlatformInterface::quoteIdentifierInFragment
remove performance test
#5683 - fixing docblock types
#5683 - cs fixes (spacing)
#5683 - mapping over results to be quoted instead of iterating via `while`
#5683 - removing useless `is_array` check: casting instead
#5683 - minor CS fix (alignment)
#5683 - Removing duplicate docs defined in the interface
#5683 - Minor docblock fixes in the `Mysql` platform
#5683 - Minor docblock fixes in the `SqlServer` platform
#5683 - Minor docblock fixes in the `Postgresql` platform
#5683 - Minor docblock fixes in the `Sqlite` platform
#5683 - Minor docblock fixes in the `IbmDb2` platform
#5683 - Simplified and fixed docblocks in `Sql92` platform
#5683 - Adding missing docblocks in `TrustingSql92Platform` platform test asset
#5683 - Simplified `Oracle` platform logic and docblocks