Bug: Calcite switch input name and value attributes overwritten

[vcolavin]

cc @patrickarlt

I came across this while working on #1. I think this issue is coming from the syncProxyInput method. The method should check whether the this.inputProxy has a name or value before assigning this.name or this.value. It should also check whether this.name or this.value is undefined, to avoid assigning the string "undefined" to the proxy input.

To reproduce:

Pass an input with a name and/or value into calcite-switch's slot:

<label>
  <calcite-switch>
    <input type="checkbox" name='some-name' value='some-value'/>
  </calcite-switch>
  Here's my label
</label>

Expected result

Expect to have calcite-switch's input element to have correct name and value attrs in the outputted DOM, e.g.

<label>
  <calcite-switch>
    <input type="checkbox" name='some-name' value='some-value'/>
  </calcite-switch>
  Here's my label
</label>

Actual result

name and value are overwritten with the string "undefined".

<label>
  <calcite-switch>
    <input type="checkbox" name='undefined' value='undefined'/>
  </calcite-switch>
  Here's my label
</label>

Note that this only happens with name and value. You could pass in some-random-attr='test' and it is maintained.

Workaround

You can put the name and value on calcite-switch directly:

<label>
  <calcite-switch  name='some-name' value='some-value'>
    <input type="checkbox"/>
  </calcite-switch>
  Here's my label
</label>

[patrickarlt]

@vcolavin like #43 (comment) since hte user is passing in the input I think that:

<label>
  <calcite-switch>
    <input type="checkbox" name='some-name' value='some-value'/>
  </calcite-switch>
  Here's my label
</label>

the values from the inputs should "win" and the result should be

<label>
  <calcite-switch name='some-name' value='some-value'>
    <input type="checkbox" name='some-name' value='some-value'/>
  </calcite-switch>
  Here's my label
</label>

THEN I think is any value switched, checked, name, value changes on either element that should be synced. You can observe attribute changes on the <input> with MutationObservers.