Multi phase problem initiation set up

[AzadSaeed]

Potentially enable the DTQP_setup_initialize to create the field structure for multi phase problems (such as case 3 in JadduShimemura example )

[danielrherber]

Can you confirm that nonlin.linkage_equality and nonlin.linkage_inequality don't cover the needed fields? https://github.com/danielrherber/dt-qp-project/blob/new-input-struct/src/DTQP_setup_initialize.m#L74-L75