SHRINK does not alter bucketize status

[randomboolean]

SHRINK on bucketized GTS does not modify bucketcount nor lastbucket.

Shrinked bucketized GTS end up with lastbuckets that are not aligned with their last data point.

Fix options:

• reset bucketize status in shrink (unbucketize)
• or update bucketize parameters in shrink (but must account for non bucket data points)
• or precise in shrink documentation the current behavior

[hbs]

SHRINK is focused on restricting the number of values, the bucketization parameters should not be altered as a result, so your last option is the one to adopt.

[randomboolean]

Documentation has been modified.