FIX: EtchNetClass missing on StackupLayer

[chenchienjacklin]

closes #536

[chenchienjacklin]

tested by

from ansys.edb.core.database import Database
from ansys.edb.core.layout.cell import Cell
from ansys.edb.core.session import session
from ansys.edb.core.layer.stackup_layer import EtchNetClass

ANSYS_EM_ROOT = r"C:\Program Files\ANSYS Inc\v261\AnsysEM"
EDB_PATH = r"C:\Users\jlin\Documents\Ansoft\Kame_MB.aedb"
with session(ANSYS_EM_ROOT, 50055):
    try:
        db = Database.open(EDB_PATH, False)
        cell: Cell = db.circuit_cells[0]
        lc = cell.layout.layer_collection
        top = lc.find_by_name("Top")
        
        print(f"etch_factor_enabled {top.etch_factor_enabled}")
        top.etch_factor_enabled = True
        print(f"etch_factor_enabled {top.etch_factor_enabled}")
        
        print(f"etch_net_class {top.etch_net_class}")
        top.etch_net_class = EtchNetClass.NO_ETCH_POWER_GROUND
        print(f"etch_net_class {top.etch_net_class}")
        
    except Exception as e:
        raise e
    finally:
        db.close()

$ python test_etch_net_class.py 
etch_factor_enabled False
etch_factor_enabled True
etch_net_class EtchNetClass.ETCH_ALL_NETS
etch_net_class EtchNetClass.NO_ETCH_POWER_GROUND

[drewm102]

@chenchienjacklin Make sure to run parse_protos.sh to update rpc_info.py for caching/buffering support.