Clean up failed cursors before transaction abort

[tanscorpio7]

Description

When we open a cursor, we pin the portal for this cursor internally. These pinned portals are then held before transaction abort in error handling to protect them from being cleaned up.
Now holding a pinned portal is only possible if the portal is in ready state. Trying to hold a pinned portal with any other status will result in error.

To fix this, we must unpin the cursor portal if it fails during a cursor fetch operation, since the portal is in failed state.

We also map the cursor does not exist error. This error is also not batch aborting.

Issues Resolved

[BABEL-4585]

Check List

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[coveralls]

Pull Request Test Coverage Report for Build 7421549123

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.005%) to 72.252%

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Totals
Change from base Build 7409492372:	0.005%
Covered Lines:	39630
Relevant Lines:	54850

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💛 - Coveralls