New release of /ui2/cl_json with patch version 21 (corresponds to the note 3568088).

Patch Level 20 cumulative release

Some more new bugs cleaned.

Corrects several regression bugs coming with PL19

/UI2/CL_JSON

• Fixed: enhanced processing of deserialization into typed TYPE REFs
• Fixed: deserialization of JSON 'null' into complex, not reference ABAP fields does not lead to exception in strict mode (details)
• Fixed: Added support for ABAP_BOOLEAN type.
• Fixed: performance optimization for deserializing strings with escaped line breaks and special characters. When you have escaped "", e.g. "\" it is still slow.
• Fixed: short dump in conversion exits routines on SERIALIZE/DESERIALIZE because of the wrong data type (OBJECTS_NOT_CHAR).
• Fixed. Added support for the timezone offsets for ISO8601.
• New: Information about the invalid field added to the exception data of move_cast_error (details)
• New: serialization now can detect "timestamps" defined with the help of data domains (details)
• New: new switch for GENERATE (optimize) and DESERIALIZE (gen_optimize) that enables optimization of generated ABAP data for REF TO DATA (fewer references, easily readable and accessible). Results in longer processing.
• New: added detection of time, date, and timestamp values on generation/deserialization into TYPE REF TO data.

Removed dependency to /ui2/cl_data_access for z_ui2_json

• Added: Open Source version of the /ui2/cl_data_access as Z_UI2_DATA_ACCESS