Can specify or unify the time unit for bench testing

[chen-qingyu]

Description

When I run catch2 benchmarks, I got some result like:

benchmark name                            samples    iterations          mean
-------------------------------------------------------------------------------
xxx                                            100           138    145.246 ns
xxx                                            100            81    245.556 ns
xxx                                            100            49    408.755 ns
xxx                                            100            35    572.086 ns
xxx                                            100           117     150.47 ns
xxx                                            100            70    287.971 ns
xxx                                            100             5     4.2428 us
xxx                                            100           100     199.36 ns

There is a microsecond in a pile of nanoseconds, which can easily cause confusion. Is there any way to unify the time unit?

Furthermore, can the precision of decimal output be standardized? For example, all outputs are to two decimal places.