Lookup table from csv file directly

• Added the new CSV lookup signature: csv(table, lookupValue, lookupColumn, valueColumn[, interpolation]).
• Kept backward compatibility with the previous 3-argument form: csv(table, lookupValue, valueColumn).
• Added optional interpolation modes when the lookup key is missing:
  • none / exact (default, no interpolation)
  • linear / lerp
  • nearest / closest
• csv, table, and lookup remain aliases of the same function.

Calcdocs-VSCode-Extension v0.1.3

Added CodeLens to show the effective value, support for VSCode 1.109