Add support for partial data placement tracing in MSPileup documents

[vkuznet]

Impact of the new feature
Allow traceability of partial data placement in MSPileup documents

Is your feature request related to a problem? Please describe.
It is part of #11537 meta-issue

Describe the solution you'd like
Add new transition attribute to MSPIleup document which will be updated with every partial data placement request. The structure we suggest is the following:

"transition": [
     {'updateTime': 1701184510, 'containerFraction': 0.5, 'customDID': 'blah', 'DN': 'blah2'},
     # another transition record
]

The transition record should contain the following attributes:

• updateTime: the UNIX timestamp of the transition request
• containerFraction: the new container fraction value
• customDID: the new custom name DID
• DN: the distinguished name of the requestor

Once this is deployed in testbed, MongoDB documents need to be updated to be consistent with the new schema

Describe alternatives you've considered
None, i.e. if we will not add it to MSPIleup document we will not have ability to perform tracing of partial data placement requests.

Additional context

• This is part of the meta issue: Support partial data placement/location for PREMIX pileup #11537
• As a part of implementation add validation of containerFraction in MSPileup to be in range 0<containerFraction<=1

[amaltaro]

@vkuznet Valentin, I'd suggest to add to the deliverables of this issue something like "Once this is deployed in testbed, MongoDB documents need to be updated to be consistent with the new schema".