Add support per channel dump-from and dump-to limitation

[kolsys]

This patch allow to configure -dump-from and -dump-to limitation per channel.

How to use

As channel name you must provide channel ID and dates with format {CHANNEL_ID}|{OLDEST_TIME}|{LATEST_TIME}

To dump only specified channel where messages not older

slackdump 'C123|2024-04-07T23:02:12' 'C321|2024-01-01T23:02:12'

To dump only specified channels where message time between specified time

slackdump 'C123|2024-01-07T23:02:12|2024-04-07T23:02:12' 'C321|2024-01-01T23:02:12|2024-03-07T23:02:12'

To dump only specified channels where message time older than specified time

slackdump 'C123||2024-04-07T23:02:12' 'C321||2024-03-07T23:02:12'

To dump all available channels but channel C123 and C321 only from specified time

slackdump '^C123|2024-04-07T23:02:12' '^C321|2024-01-01T23:02:12'

[rusq]

Hey @kolsys thanks for your contribution! It looks good, the only thing is that one test needs updating - would you be able to update it?

Once merged, I'll port this to v3.

[rusq]

see above comment

[kolsys]

Hey @kolsys thanks for your contribution! It looks good, the only thing is that one test needs updating - would you be able to update it?

Fixed.