Combine component inheritance into transpiled output

There is a performance hit whenever you use component inheritance on-device.

Add a compile-time flag that will merge child components and parent components into a single file. This reduces the performance hit for all of those components when instantiated at runtime. We could also flag certain components as "abstract", so they won't get emitted at all. (for example, the "Parent" component below could be excluded from output because it'll never be directly instantiated).

For example:

<component name="Parent">
    <script uri="common.brs" />
    <script uri="parent.brs" />
    <script>
        sub init()
            m.name = "Parent"
        end sub
    </script>
    <interface>
        <function name="CommonOperation" />
    </interface>
</component>

<component name="Child" extends="Parent">
    <script uri="common.brs" />
    <script uri="child.brs" />
    <script>
        sub init()
            m.name = "Child"
        end sub
    </script>
    <interface>
        <function name="ParentOperation" />
        <function name="CommonOperation" />
    </interface>
</component>

would transpile to:

<component name="Child">
    <script uri="common.brs" />
    <script uri="parent.brs"
    <script uri="child.brs" />
    <script>
        sub init()
            m.name = "Parent"
            m.name = "Child"
        end sub
    </script>
    <interface>
        <function name="ParentOperation" />
        <function name="CommonOperation" />
        <function name="ChildOperation" />
    </interface>
</component>

Start by locating the component inheritance transpilation entry point and the handling for the Parent and Child XML examples. Define how a compile-time flag merges scripts, initialization, and interface declarations, and how abstract components are excluded. Done means inherited components emit as one runtime component with the expected ordering and abstract components are not emitted.