add hierarachical time breakdown feature

[wuyifff]

Description

This PR refactors the Timer utility to introduce a hierarchical timer tree structure, also add a feature that timer can support manually stop.

Key Changes:

src/oops/util/Timer.cc: The Timer class now tracks its position within a call tree using TimerHelper and a new stopped_ flag to prevent duplicate time logging.

src/oops/util/TimerHelper.cc & src/oops/util/TimerHelper.h: The TimerHelper is updated to manage a new TimerTree class, including methods to navigate the tree (goDown, goUp) and to print the complete hierarchical timing structure.

src/oops/util/TimerTree.h: This new file defines the TimerTree class, which handles the creation and management of the hierarchical timer structure and includes a method to print the tree in a unix tree command like format.

Useage

We can use it as before, declare timer in the beginning of the code section and it will auto destruct when exit block. Another usage (new) is wrapping the statements we want to measure time using timer declaration and explicit timer.stop.

For example:

# statements
util::Timer timer_initial_b("DRPLanczosMinimizer", "initial_B_LMP_multiply");
lmp_.multiply(vv, pr);
B.multiply(pr, zz);
timer_initial_b.stop();
# statements