refactor the sorting approach

[Omarabdul3ziz]

instead of filtering based on the sort tag on the resource struct, sometimes we need to apply a sorting that has no equivalent field

tfgrid-sdk-go/grid-proxy/pkg/types/nodes.go

Line 54 in 953055d

_ string `sort:"free_cru"`

It is better to separate the sorting parameters into new types for each resource and validate them against their fields. also separate the sort_by and sort_order from the limit into a new struct which will be integrated only when its needed.