[Feature]: Add policy to seal long time idle segment

[longjiquan]

Is there an existing issue for this?

• [X] I have searched the existing issues

Is your feature request related to a problem? Please describe.

If users insert entities into segment continuously within a certain period of time, but they forgot to flush/(seal) it and the size of segment didn't reach the seal proportion. Under this situation, Milvus will wait these segments to be expired and during this period search latency may be a little high. We can assume that entities won't be inserted into this segment anymore, so sealLongTimeIdlePolicy will seal these segments to trigger handoff of query cluster.

Describe the solution you'd like.

No response

Describe an alternate solution.

No response

Anything else? (Additional Context)

No response

[xiaofan-luan]

/assign @yanliang567 pls help on verifying the new policy

[yanliang567]

/assign @binbinlv

[yanliang567]

released on 2.2.0