[DNM] fix: Avoid releasing unacquired memory

[wForget]

Which issue does this PR close?

Closes #1733.

Rationale for this change

The memory acquired by CometMemoryPool.grow may be less than the actual request, so CometMemoryPool.shrink may release more memory than acquired memory.

datafusion-comet/native/core/src/execution/memory_pools/unified_pool.rs

Lines 93 to 95 in 25e39ab

	self.acquire(additional)
	.unwrap_or_else(|_| panic!("Failed to acquire {} bytes", additional));
	self.used.fetch_add(additional, Relaxed);

What changes are included in this PR?

Add an acquired counter to avoid releasing more unacquired memory

How are these changes tested?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.68%. Comparing base (f09f8af) to head (5476bdb).
⚠️ Report is 1166 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1731      +/-   ##
============================================
+ Coverage     56.12%   58.68%   +2.55%     
- Complexity      976     1137     +161     
============================================
  Files           119      129      +10     
  Lines         11743    12687     +944     
  Branches       2251     2373     +122     
============================================
+ Hits           6591     7445     +854     
- Misses         4012     4056      +44     
- Partials       1140     1186      +46     

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