This commit progressively enhances the existing server-side price
filtering to be possible from the client-side, without disrupting the
current map state.
Embed data-price onto each <g> element to represent that
Section record’s price.
When the corresponding <input type="radio"> element is checked,
route the input event to the seats#filterSeats action. The
seats#filterSeats action will use the checked radio button’s price
to determine which Sections should be highlighted, and which Sections
should have their opacity decreased.
The values for the opacity attribute that indicate inclusion and
exclusion are encoded (as data-included-opacity and
data-excluded-opacity) into the <g> elements that represent the
Sections.
Additionally, wrap the filter <form> element’s <input type="submit">
element in a <noscript> element.
When JavaScript is enabled in the client’s web browser, the new
Stimulus-powered event routing will apply the filter changes in
real-time, without the need to submit the <form>.
However, when JavaScript is disabled, the <input type="submit"> will
render, and the <form> will filter the map by making HTTP requests to
the server.
