Use C++ standard library components instead of the custom implementations in CTA/common/

Problem

When the CTA project started being developed (around 10 years ago) several of the C++ standard library components were not yet available to us (as they were only introduced with C++11 and more recent versions).

As a result, most of these components (threads, synchronisation primitives, etc.) had to be implemented by us, usually on top of POSIX.

However, since then we have moved to much more recent C++ standards (with a recent upgrade to C++20 - #1254 (closed)). This means that most of these functions are no longer necessary and can be replaced by their C++ standard equivalents.

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As pointed out by @mdavis in this comment:

in the rest of CTA we are using our own thread implementation (in common/threading). That's for historical reasons (std::thread is a C++11 feature, which was not available to us when the project started) but perhaps now we should clean up and standardise. Let's bring this topic up in a dev meeting.

Objective

We can split this work into the following tasks:

1. Look into the CTA/common/ directory and list all the components that can be replaced by their modern C++ (C++17/20) equivalents. Check also SonarCloud for suggestions (link) on this and other directories.
2. Evaluate the effort required to implement each of these changes and review with the team.
3. Implement.