Function: setOracleMode(OracleMode _mode)
This function sets the oracle mode.
Inputs
_modeControl: Fully controlled by the caller.
Constraints: None.
Impact: An oracle mode to set the mode of.
Branches and code coverage
Intended branches
Set the oracle mode.
Negative behavior
Revert if the caller is not an owner.
Revert if the mode is not a valid mode.