♻️ [Database] Deprecate `db.pool.size.*` settings

[Coduz]

This PR deprecates commons.db.pool.size.min and commons.db.pool.size.max settings since they have changed their meaning/usage after #4067

Related Issue This PR improves changes made in #4067

Description of the solution adopted Deprecated usage of:

• commons.db.pool.size.min - not used since $4067
• commons.db.pool.size.max - replaced by commons.db.pool.size due to #4067
• commons.db.pool.idle.timeout - not used since $4067

Removed:

• commons.db.pool.size.initial - not used nor referenced
• commons.db.pool.borrow.timeout - not used nor referenced

which were no longer used.

Introduced a new commons.db.pool.size setting to manage the fixed pool size.

Screenshots None

Any side note on the changes made Introduced UPGRADE_NOTES.md file to start maintaining a verbose upgrade notes log for notable changes in version

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 73.91304% with 12 lines in your changes missing coverage. Please review.

Project coverage is 16.79%. Comparing base (4116da6) to head (86528ae). Report is 10 commits behind head on develop.

Files with missing lines	Patch %	Lines
...java/org/eclipse/kapua/commons/jpa/DataSource.java	70.73%	9 Missing and 3 partials :warning:

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #4112      +/-   ##
=============================================
+ Coverage      16.75%   16.79%   +0.03%     
  Complexity        22       22              
=============================================
  Files           2037     2037              
  Lines          52796    52835      +39     
  Branches        4438     4441       +3     
=============================================
+ Hits            8847     8874      +27     
- Misses         43551    43560       +9     
- Partials         398      401       +3     

Files with missing lines	Coverage Δ
...kapua/commons/setting/system/SystemSettingKey.java	100.00% <100.00%> (ø)
...java/org/eclipse/kapua/commons/jpa/DataSource.java	75.92% <70.73%> (-18.20%)	:arrow_down: