PriceOracle: get_aggregate_price method input field issues

[SaxenaKaustubh]

While calculating PriceOracle aggregate pricing using the get_aggregate_price method, I noticed the following issues:

1. trim: A decimal value e.g. 1.2 gets truncated to int e.g.1.
2. oracle_document_id: A decimal value e.g. 1.2 gets truncated to int e.g.1.
3. There is no input validation on the oracle_document_id field for an input of None.
4. There is no input validation on BaseAsset and QuoteAsset fields. All of the following values are acceptable:
   • None
   • "Invalid"
   • 123
   • -1
   • 0
   • 1.2
   • "0158415500000000C1F76FF6ECB0BAC600000000A"
   • "H"
   • "HB"
   • "HBAR"
   • ""