[Feature] Add Chart To econometrics.correlation_matrix

[deeleeramone]

1. Why?:

   • More charts are more better.
   • obb.econometrics.correlation_matrix was missing the "method" parameter.

2. What?:

   • Adds a visualization for obb.econometrics.correlation_matrix
   • Adds a parameter for the correlation method - ["pearson", "kendall", "spearman"]
   • Adds a Charting method, create_correlation_matrix, to create the chart from external data.

3. Impact:

   • Enhances the charting library with a traditional, diagonal, masked, correlation matrix heatmap.
   • API-compatible chart.

4. Testing Done:

   • Unit and integration tests.

Both blocks should create the same chart, except the second will be sorted alphabetically.

from openbb import obb

symbols = "SPY,NVDA,AAPL,MSFT,GOOG,PLTR,TSLA".split(",")
data = (
    obb.equity.price.historical(symbols)
    .to_df()
    .pivot(
        values="close",
        columns="symbol",
    )
).filter(items=symbols, axis=1)
corr = obb.econometrics.correlation_matrix(data=data, method="pearson", chart=True)
corr.show()

from openbb import obb

data = obb.equity.price.historical("SPY,NVDA,AAPL,MSFT,GOOG,PLTR,TSLA", provider="yfinance")
data.charting.create_correlation_matrix(data.results).show()