Equivolume - volume as candle width

Do price action and volume really need to be on separate graphs? Why not display them both on a single graph and reduce the clutter? Presenting Equivolume candles here on TradingView - inspired by the NinjaTrader implementation

This indicator allows you to view traditional OHLC candles but with the additional ability to see relative volume through variations of width and/or transparency

Explanation
- Wide and/or full colour candles have the highest volume
- Thin and/or highly transparent candles have the lowest volume
- The following diagram shows the Equivolume indicator as well as a traditional volume graph along the bottom. You can see that when the volume is highest, the candle is widest and also the most intense color.

- The `Lookback candle count` user parameter specifies the number of candles to use in order to locate the highest volume within that range. All other candle widths in the range will be adjusted relative to this highest volume

Tips
- Toggle off the visibility of the original graph for the instrument to get the best view of the candles when using variable transparency

Gotchas
- Due to a Pine Script limitation a maximum of 500 variable width candles can be drawn on the chart
- If `Lookback candle count` is higher than the total number of available candles for the instrument, then the indicator will fail and not display anything. I’m still investigating how to handle this case better
- Be aware if you are using the `High` setting for the `Transparency range` parameter, candles with the lowest volume will be virtually invisible

Notes de version:

The wicks don't seem to appear unless I specify a `border_width`

Notes de version:

Fix so that if you choose a `lookback` range greater than the number of candles available, the chart will continue to work

Notes de version:

Show the `volume` amount as an additional value next to the indicator name and price