Clear packets by specifying a range of sequence numbers to clear

[romac]

Summary

Add a --packet-sequences=SEQS flag to the clear packets CLI for clearing only the packets with the given sequence numbers on the specified chain and channel.

Problem definition

See #3750

Proposal

Add a --packet-sequences flag to the clear packets CLI.

This flag accepts a list of ranges of sequence numbers to clear (--packet-sequences=SEQS), with the following format (in EBNF):

SEQS        = list
list        = item { "," list }
item        = seq | range
range       = upper-range | lower-range | full-range
upper-range = seq ".."
lower-range = ".." seq
full-range  = seq ".." seq
seq         = integer

Ranges are bounded inclusively below and above. The range start..end contains all values with start <= x <= end. It is empty if start > end.

Examples

Value	Meaning
1	Clear a single packet with sequence 1
1,2,3	Clear packets with sequence numbers 1, 2, and 3
..20	Clear all packets with sequence numbers less than or equal to 20
10..	Clear all packets with sequence numbers greater than or equal to 10
10..20	Clear all packets with sequence numbers 10, 11, 12, ..., 20
2,4..6,12,14..17,21,30..	Clear packets with sequence numbers 2, 4, 5, 6,
30..,21,12,14..17,4..6,2	Same as previous, the order in which the ranges are specified does not matter

[sryps]

I was just about to create an issue for this, I'd like to upvote the value of this! :)