Uniformize postprocess output precision

[AmishgaAlphonius]

Description

In response to the the issue #1096, this PR uniformize precision of outputted values using the log precision parameter. All postprocessing tables outputted on terminal are now displayed in scientific notation.

Testing

All affected tests were updated.

Checklist (will be removed when merged)

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Code related list:

• All in-code documentation related to this PR is up to date (Doxygen format)
• Lethe documentation is up to date
• The branch is rebased onto master
• Code is indented with indent-all and .prm files (examples and tests) with prm-indent
• If parameters are modified, the tests and the documentation of examples are up to date
• Changelog (CHANGELOG.md) is up to date if the refactor affects the user experience or the codebase

Pull request related list:

• No other PR is open related to this refactoring
• Labels are applied
• There are at least 2 reviewers (or 1 if small feature) excluding the responsible for the merge
• If this PR closes an issue or is related to a project, it is linked in the "Projects" or "Development" section
• If any future works is planed, an issue is opened
• The PR description is cleaned and ready for merge