chore: replace library tinydir with std::filesystem

[federico-sysdig]

What type of PR is this?
/kind cleanup

Any specific area of the project related to this PR?
/area build

Does this PR require a change in the driver versions?
no

What this PR does / why we need it:
Replaces the usage of library tinydir, used only once to scan a directory of Lua source files, with std::filesystem from the standard C++ library. The dependency from tinydir is also removed from the project.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:
I'd like to know how I can get evidence that the modified function is behaving the same or, if not possible, if someone can provide some support for adding a test for it.

Does this PR introduce a user-facing change?:

NONE

[FedeDP]

Thanks for this great cleanup, love dropping deps!!

I'd like to know how I can get evidence that the modified function is behaving the same or, if not possible, if someone can provide some support for adding a test for it.

I think we need to write unit tests for get_chisel_list :)
You can create a new test folder under userspace/libsinsp/test and add a new test there? Of course the new folder should only be included when we build with chisels enabled.

[FedeDP]

This LGTM; the code is pretty small and the logic very simple, i think it's good to go.
/approve

[poiana]

LGTM label has been added.

Git tree hash: d18399c229e6b1739835f2c118970753128c7380

[FedeDP]

/milestone 0.14.0

[jasondellaluce]

/approve

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: FedeDP, federico-sysdig, jasondellaluce

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [FedeDP,jasondellaluce]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment