Price discovery indicator

Gives an ability to show places where price drops more than n percent in x candles. Use cases: see dips of btc, get a notification when a stablecoin goes crazy, validate that webhook integration works as expected using keep alive messages.

Features included:
- Price dip alerts. Create an alert that sends a notification every time price dips more than expected (yellow zone at the chart).
- Percentage drop threshold. Define how many percents price should drop to trigger an alert and to show a yellow zone.
- Candles length threshold. Define within how many candles this drop should happen. If price drops in 2% within 10 candles, but this option is 5 - the alert will not be triggered because price dropped not as fast as expected.
- Templates of messages on price dip and price recovery. Set your message that should be triggered with alert.
- Keep alive feature. Set to trigger keep alive alerts every period. Can be helpful if you don't check charts often - this feature will trigger alert every period with "hey, the integration is alive" message. I use it to validate on weekly basis that tradingview triggers my alerts (example: you created an alert with expiration date and forgot to recreate it), that webhook integration receives these alerts, that the integration sends these alerts to telegram. Example: I expect to see this message every monday's morning, otherwise something is broken and I have to check what is wrong with my alerting system.