⚡️ Unclogger updates / improvements

[Rikj000]

Improve the open trade unclogger by:

• 🔳 Implementing more/better indicators readily available inside the dataframe being used
• ☑️ Reducing code duplication in it's checks as much as possible

[Rikj000]

• ☑️ Restrict the unclogger to only unclog if the current trend is flagged as "bad"
• ☑️ Implement a configurable buy cooldown window so the same pair can't be bought again for X candles after unclogging

[Rikj000]

☑️ Add more weight to more recent data and less weight to older data used in the sell___unclogger_trend_lookback_candles_window for the sell___unclogger_trend_lookback_candles_window_percentage_needed check.

The idea is inspired off EMAs (Exponential Moving Averages) where they act upon the same principle.

The amount of weight added in the near candles and subtracted of the oldest candles should balance out when a sum of all values used to multiply is taken.
Also the weight by how much we add / subtract will be important, so I want to make it configurable.
Example: The newest candle has a weight of x2, oldest candle a weight of x(1/2) with incremental steps in between (steps depending on the amount of candles in the lookback window), middle candle should be x1

Here the newest candles will be 4 times as important as the oldest 2 = 4 * (1/2)
Our configurable parameter value is 2 in this case, name proposition unclogger_trend_lookback_candles_window_recent_past_weight_separator (It's clear but not a fan due to the length..)

[Rikj000]

☑️ sell_profits_only=true specifically for normal sell signals, so it won't mess with the custom_sell of the unclogger during HyperOpt.
Previously it stopped the unclogger from working since it's also a "sell signal", which lead to a hodl bot. This should resolve that issue though and be a step towards: #37

[Rikj000]

🔳 ⚡️ Trend specific Unclogger configurations