feat: configurable minimum scan age

[m-rots]

Instead of defaulting to 5 minutes, this PR allows the user to set a custom minimum scan age manually.
The default is still set at 5 minutes.

Config

The config now features a minimum-age field which should be given a string in the following format:

• 1s if the min-age should be set at 1 second.
• 5m if the min-age should be set at 5 minutes.
• 1m30s if the min-age should be set at 1 minute and 30 seconds.
• 1h if the min-age should be set at 1 hour.

# 1 minute (60 seconds)
minimum-age: 60s

# 5 minutes
minimum-age: 5m

# 30 minutes (0.5 hours)
# commas are not supported!
minimum-age: 0.5h

ns, us and ms are supported as well, but should not be used by nor communicated to the user.
Values such as days, months and years are not supported.

When a number is given instead, it defaults to nanoseconds, the smallest time unit.

Processor

The processor now accepts MinimumAge within its config as time.Duration
This minimum age is used within the datastore's GetMatching(minAge time.Duration) function.

All datastore tests have been updated accordingly

Logging

A new INFO log is printed at the very start which prints the processor's configuration:

• anchors
• max_retries
• min_age

Small changes

I've also updated the CMD logs to display lidarr in the initialised triggers.