Add support for replaceable models in Modelica templates

[AntoineGautier]

Currently ctrl-flow parser can only handle replaceable components inside Modelica templates.
This ticket is to add support for replaceable models.
Additional details are provided in the joint MBL issue lbl-srg/modelica-buildings#3507.

[AntoineGautier]

There is another issue that the branch issue3507_replaceableClass reveals.
In this branch, the component secRel of Buildings.Templates.AirHandlersFans.Components.OutdoorReliefReturnSection.MixedAirWithDamper is a simple replaceable component that should be visible in the configuration panel, but it isn't.
The corresponding option object in templates.json is:

    {
      "modelicaPath": "Buildings.Templates.AirHandlersFans.Components.OutdoorReliefReturnSection.MixedAirWithDamper.secRel",
      "type": "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReturnFan",
      "value": "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReturnFan",
      "name": "Relief/return air section",
      "group": "Configuration",
      "tab": "",
      "visible": true,
      "modifiers": {...},
      "enable": true,
      "choiceModifiers": {},
      "options": [
        "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReturnFan",
        "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReliefFan",
        "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReliefDamper"
      ],
      "definition": false,
      "replaceable": true
    },

The following mods is not created by new ConfigContext:

    "secOutRel.secRel": {
      "value": "Buildings.Templates.AirHandlersFans.Components.ReliefReturnSection.ReliefDamper",
      "optionPath": "Buildings.Templates.AirHandlersFans.Components.OutdoorReliefReturnSection.MixedAirWithDamper.secRel"
    },