DFP-16: Introducing variable / individual freeze times for funds invested in portfolios

Please format using the guidelines provided here: DMP-2: DFP Purpose and Guidelines.

Otherwise, you can make a feature request at https://feedback.dhedge.org/.

It seems variable freezing, and adding other fees are different features, please split up this request into multiple DFPs.

And management fee is already a feature which passed governance, seen here: DFP-8: Add Streaming Fee Option for Pools.