Intent stuck in WITHDRAWING state with FlowObjective intent compiler

Steps to reproduce:

cfg set org.onosproject.provider.nil.NullProviders deviceCount 7
cfg set org.onosproject.provider.nil.NullProviders topoShape linear
cfg set org.onosproject.provider.nil.NullProviders enabled true
cfg set org.onosproject.net.intent.impl.IntentManager skipReleaseResourcesOnWithdrawal true
cfg set org.onosproject.net.intent.impl.compiler.IntentConfigurableRegistrator useFlowObjectives true
cfg set org.onosproject.net.intent.impl.compiler.IntentConfigurableRegistrator defaultFlowObjectiveCompiler org.onosproject.net.intent.impl.compiler.LinkCollectionIntentObjectiveCompiler
push-test-intents -i null:0000000000000001/6 null:0000000000000007/5 1 1
push-test-intents -w null:0000000000000001/6 null:0000000000000007/5 1 1

Update from [~trtc008056]
Reasons makes Intent stuck in WITHDRAWING state:
1. The patch for CORD-1180 caused next objective queued in the objective system if there is no next group for that next objective.

2. Default single table pipeline removes next group from flow objective store when removing forwarding objective.

3. The flow objective Intent installer will remove forwarding objective first, then remove next objective.

4. The flow objective Intent install will wait until all objective context completed, however, according to reason 1, 2 and 3, the next objective will be queued forever since there will be no next group in the store.
So the Intent state will stuck in WITHDRAWING until the Intent manager retry.

To fix this issue, we need to modify default single table pipeline, make it not remove next group when removing forwarding objective.