Add supported actions list to table in P4TC

[vbnogueira]

A P4 table has a list of actions it supports, for example:

table smac {
    key = { outCtrl.outputPort : exact; }
    actions = {
        Drop_action;
        Rewrite_smac;
    }
}

The actions list specifies which actions may be used as default_action of this table or as a table entry action.

We must support this in P4TC