[receiver/vcenter] Adds vCenter VSAN Host metrics

[BominRahmani]

Description:

The following PR adds VSAN host metric collection. The following metrics are collected

vcenter.host.vsan.throughput          (direction={read/write})
vcenter.host.vsan.iops                (direction={read/write})
vcenter.host.vsan.congestions
vcenter.host.vsan.cache.hit_rate
vcenter.host.vsan.latency.avg         (direction={read/write})

Link to tracking Issue: #33556

Testing:
Added mock data fields in order to test vsan host metric scraping. Updated golden test file output.

Documentation:
Updated documentation using make generate