EVM Node: Fix timing advertized by the `blueprint_applied` event

The timing advertized was limited to the function modifying the session_state, and excluding the actual application of the blueprint and commit to the on-disk stores.

This patch addresses this by introducing a new helper with_timing_f_e, where f stands for function (i.e., the continution called by the helper also takes the result of the computation), and e stands for error (i.e., the computation is in the error monad, not Lwt).

Manually testing the MR

Run an observer with and without this patch. I go from

Dec 10 13:51:41.541: Applied a blueprint for level 4172872 at 2024-11-07T20:49:05Z containing 1
Dec 10 13:51:41.541:   transactions for 4547719 gas leading to creating block
Dec 10 13:51:41.541:   0xd9ba4f59918b1f81cefdfd29a8e764782dda0e23b20108a2671782368[...] in
Dec 10 13:51:41.541:   1.224us.

to something like

Dec 10 13:53:09.861: Applied a blueprint for level 4172901 at 2024-11-07T20:50:53Z containing 1
Dec 10 13:53:09.861:   transactions for 4547661 gas leading to creating block
Dec 10 13:53:09.861:   0xf2e38ae160838c6b94fc8811cbe5487bf883684712e4e32cf791e4c21[...] in
Dec 10 13:53:09.861:   23.589ms.

The latter makes more sense.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
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