Add a short format for timestamps

[tksm]

What would you like to be added:

I would like to add a short format for timestamps for readability, such as 01-02 15:04:05. It might be a form --timestamps=short or a new flag like --short-timestamps.

Though the current format for timestamps 2006-01-02T15:04:05.000000000Z07:00 is easy to be parsed by programs, it is a bit lengthy for humans.

Candidates for the short timestamp format are as follows. I prefer the 01-02 15:04:05 format.

format (Go’s time format)	note
01-02 15:04:05	time.DateTime without year
2006-01-02 15:04:05	time.DateTime
Jan _2 15:04:05	time.Stamp (no ambiguity in the order of month and date)
15:04:05	time.TimeOnly
2006-01-02T15:04:05.000000000Z07:00	RFC3339Nano but with trailing zeros (Current format)

We can also colorize the timestamp field to improve the readability, but I guess discussing it in another issue is better.

Why is this needed:

The flag --timestamps is helpful because it converts times to local time by default. But the format is a bit long to use in daily use.

Here is the example of the current output with --timestamps.

kindnet-flqlg kindnet-cni 2023-03-11T09:52:10.563885300+09:00 I0311 00:52:10.563620       1 main.go:250] Node kind-worker2 has CIDR [10.244.2.0/24]
kindnet-flqlg kindnet-cni 2023-03-11T09:52:10.563897200+09:00 I0311 00:52:10.563760       1 main.go:223] Handling node with IPs: map[172.20.0.3:{}]
kindnet-flqlg kindnet-cni 2023-03-11T09:52:10.563908200+09:00 I0311 00:52:10.563790       1 main.go:250] Node kind-worker3 has CIDR [10.244.1.0/24]

If we have a short format like 01-02 15:04:05, it would be much easier to read.

kindnet-flqlg kindnet-cni 03-11 09:52:10 I0311 00:52:10.563620       1 main.go:250] Node kind-worker2 has CIDR [10.244.2.0/24]
kindnet-flqlg kindnet-cni 03-11 09:52:10 I0311 00:52:10.563760       1 main.go:223] Handling node with IPs: map[172.20.0.3:{}]
kindnet-flqlg kindnet-cni 03-11 09:52:10 I0311 00:52:10.563790       1 main.go:250] Node kind-worker3 has CIDR [10.244.1.0/24]