refactor

    TRY.
        lv_xstring = cl_bcs_convert=>string_to_xstring(
                       iv_string     = lv_value
                       iv_codepage   = lv_encoding
                       iv_add_bom    = 'X' ).
      CATCH cx_bcs.
    ENDTRY.

to use CL_ABAP_CONV_IN_CE or CL_ABAP_CONV_OUT_CE

BOMs defined in cl_abap_char_utilities=>byte_order_mark_*

Describe the bug
Calling procedure with CommandBehavior.SchemaOnly behavior wraps sql with SET FMTONLY ON and SET FMTONLY OFF lines which results in following errors:

// for fully-qualified name (db.schema.proc)
Attempt to locate entry in sysdatabases for database 'SET FMTONLY ON
TestDataCore' by name failed - no entry found under that name. Make sure that name is entered proper

the shared_storage_type terraform variable has been removed recently but some dead references can still be found throughout the project.

supersedes #286