Enum valued components need a default or have to be required

[wurzka]

This issue is motivated by https://github.com/SAP/abap-file-formats-tools/issues/150 Following types need a default value or have to become required:

• [x] CLAS https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/clas/type/zif_aff_clas_v1.intf.abap#L6
• [ ] DSFI https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/dsfi/type/zif_aff_dsfi_v1.intf.abap#L8
• [x] ENHO 1 https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/enho/type/zif_aff_enho_v1.intf.abap#L19
• [ ] ENHO 2 https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/enho/type/zif_aff_enho_v1.intf.abap#L105
• [ ] ENHO 3 https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/enho/type/zif_aff_enho_v1.intf.abap#L39
• [x] FUGR https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/fugr/type/zif_aff_fugr_v1.intf.abap#L7
• [x] FUNC https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/fugr/type/zif_aff_func_v1.intf.abap#L146
• [x] INTF https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/intf/type/zif_aff_intf_v1.intf.abap#L6
• [ ] SCP1 https://github.com/SAP/abap-file-formats/blob/515386378e9c1269433ee378fa806a58b54964d1/file-formats/scp1/type/zif_aff_scp1_v1.intf.abap#L77

[wurzka]

ENHO 2 and ENHO 3 will be fixed when #409 is addressed.