Wrong dimensions in `condition` bits does not throw error

<neuroml xmlns="http://www.neuroml.org/schema/neuroml2"  xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.neuroml.org/schema/neuroml2 https://raw.github.com/NeuroML/NeuroML2/development/Schemas/NeuroML2/NeuroML_v2.3.1.xsd" id="kd3">
    <ionChannelHH id="kd3" species="K" conductance="10 pS">
        <annotation/>
        <gate id="n" instances="1" type="gateHHrates">
            <q10Settings type="q10ExpTemp" q10Factor="3" experimentalTemp="16 degC"/>
            <forwardRate type="HHNearlyExpLinearRate" rate="0.02 per_ms" midpoint="20 mV" scale="9 mV"/>
            <reverseRate type="HHNearlyExpLinearRate" rate="-0.002 per_ms" midpoint="20 mV" scale="-9 mV"/>
        </gate>
    </ionChannelHH>
    <ComponentType name="HHNearlyExpLinearRate" extends="baseHHRate" description="A HHExpLinearRate, but not quite">
        <Parameter name="scale" dimension="voltage"/>
        <Parameter name="midpoint" dimension="voltage"/>
        <Parameter name="rate" dimension="per_time"/>
        <Dynamics>
            <DerivedVariable name="x" dimension="voltage" value="(v - midpoint)"/>
            <ConditionalDerivedVariable name="r" dimension="per_time" exposure="r">
                <!-- the condition below should throw an error, the value bit should also throw an error, dimensions are wrong in both places -->
                <Case condition="x .neq. 0" value="rate * x/(1 - exp(0 - x/scale))"/>
                <Case value="rate"/>
            </ConditionalDerivedVariable>
        </Dynamics>
    </ComponentType>
</neuroml>

Reproduce the issue with the NeuroML XML example, focusing on the condition and value expressions in the ConditionalDerivedVariable. Trace jLEMS's dimension validation for those expressions and add coverage showing that both mismatches raise errors; done means the supplied example no longer passes silently.