Add Fluid V2 compatibility layer
Fluid backporter should be v1 and v2 compatible (based on the version switch).
[FEATURE] Provide version switch for backporting Fluid v1 and v2
Depending on the version switch from Settings.yaml, backporter can
backport Fluid from Flow v1 and Flow v2.
Add FluidVersionStrategy which implements concrete backporter rules
for each version.
Rules for v2 will be tuned in the following changes