This PR adds three new UDFs for decoding topics of numeric and string types from contract data and method ids.

I've checked that:

• the query produces the intended results
  Validation via this Dune Query https://dune.xyz/queries/217753
• [ n/a , no new folder ] the folder name matches the schema name
• [ n/a, no schema reference ] the schema name exists in Dune
• [ I don't see the other functions in this dir following this fn_ convention?] views are prefixed with view_, functions with fn_.
• the filename matches the defined view, table or function and ends with .sql
• each file has only one view, table or function defined
• [ n/a, no column names] column names are lowercase_snake_cased

Originally posted by @dot2dotseurat in duneanalytics/spellbook#515