Add Trapping Rainwater problem implementation (Two Pointer Approach) (#6990)

* Add Trapping Rainwater problem implementation (Two Pointer Approach)

* Add Wikipedia reference link for Trapping Rainwater problem

* fix: format TrappingRainwater.java for CI check

* fix: add package and resolve checkstyle errors for TrappingRainwater.java

* fix: declare TrappingRainwater as final to pass Checkstyle

* Add test cases for TrappingRainwater algorithm

* Add test cases for TrappingRainwater algorithm

* Move TrappingRainwater algorithm to stacks package

* Fix: Move TrappingRainwater to stacks and normalize newline in JugglerSequence

* Fix: Normalize newline in JugglerSequence to ensure test consistency

* Fix: Normalize newline in JugglerSequence and remove return statement

* Add JaCoCo plugin for code coverage reporting

* Revert pom.xml to original version from master

* Fix: Revert the pom.xml file

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Co-authored-by: Deniz Altunkapan <deniz.altunkapan@outlook.com>