Test repository selection

[siegfriedweber]

Tests stackabletech/agent#229

The agent-integration-tests now serve the repositories which are required for the test case. An asynchronous context is necessary which makes it impossible to use TemporaryResource because asynchronous Drop traits are not supported yet. Also the assertion framework cannot be used anymore because an assertion would panic if it is not met. This would skip the cleanup which would be done in the Drop trait.

The ad-hoc repositories increase the convenience on the one hand but on the other hand they decrease it. Therefore the other test cases are not converted yet to these ad-hoc repositories. If the code proves useful after a while then it can be moved to the integration-test-commons.

[maltesander]

LGTM. Just one remark, you seem to mix curly and normal parenthesis on e.g. format! macro.
I do not see the difference in usage here, so i would keep it consistent? Or is it on purpose?

rfc expression macros
playground example

[siegfriedweber]

LGTM. Just one remark, you seem to mix curly and normal parenthesis on e.g. format! macro.
I do not see the difference in usage here, so i would keep it consistent? Or is it on purpose?

rfc expression macros
playground example

I unified the handling of multiline string literals. I changed all indoc, format and formatdoc macros to use parentheses because they are expressions, not blocks. (I must admit that I used sometimes curly braces because then cargo fmt didn't get into my way.)