rocketchat upgrade hooks

[LuluGO]

Added pre upgrade and post hooks to create a volume, back up mongodb data before switching from deployment to replicaset and therefore dropping the PVC with all the data. Post upgrade hook restores data into replicaset.

[CLAassistant]

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2 out of 33 committers have signed the CLA.

✅ nitisht
✅ LuluGO
❌ helgi
❌ michaelbeaumont
❌ k8s-ci-robot
❌ sebastien-prudhomme
❌ s12chung
❌ cw-ozaki
❌ smcavallo
❌ tompscanlan
❌ prateekpandey14
❌ ElfoLiNk
❌ ctrox
❌ marc-sensenich
❌ gouglhupf
❌ skalinets
❌ denis111
❌ batazor
❌ kytart
❌ mscbpi
❌ legal90
❌ TristanPeers
❌ LittleWhiteYA
❌ tompizmor
❌ KIVagant
❌ YoussB
❌ Ngob
❌ okgolove
❌ rverma-nikiai
❌ asherf
❌ startnow65
❌ davidkarlsen
❌ concaf
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