adds: SCIP::getDual

[fuookami]

When i using scip as rmp solver in column generation algorithm, i need to get the dual variable solution, at the same time, presolving and heuristics should be set off, like here:

val solver = ScipLinearSolver(
    config = config,
    callBack = callBack.copy()
        .configuration { _, model, _, _ ->
            model.setPresolving(SCIP_ParamSetting.SCIP_PARAMSETTING_OFF, true)
            model.setHeuristics(SCIP_ParamSetting.SCIP_PARAMSETTING_OFF, true)
            ok
        }
        .analyzingSolution { _, model, _, constraints ->
            dualSolution = constraints.map {
                Flt64(model.getDual(it))
            }
            ok
        }
)

[fuookami]

Sample code snippet from: https://github.com/fuookami/ospf-kotlin/blob/2a5b7878ed32949bd0da25833048b536e86c93ba/ospf-kotlin-core-plugin/ospf-kotlin-core-plugin-scip/src/main/fuookami/ospf/kotlin/core/backend/plugins/scip/ScipColumnGenerationSolver.kt#L196