Improve LICENSE & NOTICE files

[AlexanderLanin]

Link to corresponding Eclipse ticket: https://gitlab.eclipse.org/eclipsefdn/emo-team/iplab/-/issues/21148

Scope:

• Have a license file and a notice file in each repository
• Every file hast to have a license notice in the file header

An improvement of the current files was suggested by @johannes-esr, I've converted this to git: 0e13b83

However, eclipse experts said that while that is a "good start", we actually should look into https://reuse.software/

Tasks:

• Apply recommendations from reuse.software about where to put what files etc
• Provide summary on cli / actions from reuse.software, so that we can decide whether we want to use it. Might e.g. replace our cr_checker?

[MaximilianSoerenPollak]

I just tried it out a bit inside docs-as-code, the 'reuse' software.

It seems rather straight forward and very configurable. Only Issue that we have to get around / find a solution for is that it can not recognize some file formats. Mainly BUILD files.

There the automatic solution is to have a .license file inside the same directory, but unsure if this is good. Or if we should just add the 'template strings' manual or via our copyright adder?

[FScholPer]

@johannes-esr can you please review 0e13b83

[MaximilianSoerenPollak]

This is the Apache 2.0 file that reuse offers if you select it. https://github.com/spdx/license-list-data/blob/main/text/Apache-2.0.txt