extension's approval dialogue informational tooltips

[TalDerei]

related to https://github.com/penumbra-zone/web/issues/1394.

Although our approval dialogue is still an improvement largely over the current status quo of blind signing, it will increasingly reveal its limitations as our functionality expands. For instance, consider this sample send max transaction. Although the fee deduction logic functions correctly, it's confusing that the amount shown in the "output" section is reduced without a clear explanation that fees were deducted from the sent amount. Taking a step back, it’s not even clear what these actions actually are.

In relation with #1394, we should add informational tooltips to provide users with sufficient context about the elements displayed in the approval dialogue.

[TalDerei]

superseded by a design that will delineate a summary of transaction effects instead