[Feature] Add PCE (Personal Consumption Expenditures) reports to Economy

[deeleeramone]

1. Why?:

   • PCE is the Federal Reserve's preferred inflation index, and is a key component in the Board's interest rate policy.

2. What?:

   • Data is from FRED.
   • obb.economy.pce()
   • The results can be turned to look exactly as they do in the release tables: https://fred.stlouisfed.org/release?rid=54
   • Each date and category is one API call, the example below calls the default, "personal_income".

3. Impact:

   • More data to maintain

4. Testing Done:

   • Unit/integration

from openbb import obb
data = obb.economy.pce(date="2024-05-01,2023-05-01,2024-04-01")
df = data.to_df(index=None).pivot(columns="date", index=["line", "level", "element_id", "parent_id", "children", "symbol", "name", "units"], values="value")
df = df[df.columns[::-1]]

df

5. Reviewer Notes (optional):

   • If running all economy integration tests, FRED will cause your API key to get rate-limited and you will be timed out for several minutes.