♻️ [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 :fix: set hikari configuration pool to fixed size (more performant) #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]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 16.81%. Comparing base (57f10be) to head (dc4c9b4).
Report is 2 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop    #4112   +/-   ##
==========================================
  Coverage      16.81%   16.81%           
  Complexity        22       22           
==========================================
  Files           2019     2019           
  Lines          52431    52432    +1     
  Branches        4421     4421           
==========================================
+ Hits            8816     8817    +1     
  Misses         43218    43218           
  Partials         397      397           

Files with missing lines	Coverage Δ
...java/org/eclipse/kapua/commons/jpa/DataSource.java	94.11% <100.00%> (ø)
...kapua/commons/setting/system/SystemSettingKey.java	100.00% <100.00%> (ø)