Update the Eclipse SDK TP's slf4j-api to 2.0.7 and remove 1.7 version

[HannesWell]

Since version 2.0.7 the slf4j.api bundle exports the user-api package 'org.slf4j' in version 2.x.y and 1.7.36.
This allows to also use libraries, which are programmed against slf4j-1 and import the package 'org.slf4j' with an exclusive upper bound of 2 like '[1.7,2)', with the slf4-api version 2 in OSGi environments.

According to SLF4J the client/user facing API is compatible with slf4j-1:

• https://www.slf4j.org/faq.html#changesInVersion200
• https://www.slf4j.org/faq.html#compatibility

Only the logging-backends/bindings/providers have match the requirements of the specific slf4j version.

The corresponding SLF4J issue and change is

• https://jira.qos.ch/browse/SLF4J-579
• SLFJ4-579: Export client packages of slf4j-api in version 1 qos-ch/slf4j#331

Fixes #588
Fixes #682

[HannesWell]

Since version 2 the slf4j-api uses the ServiceLoader mechanism and requires a 'Service Loader Mediator' implementation in an OSGi runtime. Therefore the Apache Aries SPI Fly Dynamic Weaving Bundle is added with this change.

I'll also experiment with the Aries SPI Fly Dynamic Weaving Framework Extension, which is a fragment to the system bundle and therefore hopefully does not need to be activated 'manually' through a corresponding Product configuration. If that does not work as expected I think the auto-start defaults of PDE's product editor should be adjusted to include that bundle too (if present).

[HannesWell]

Hmm. Almost. Looks like sshd-osgi imports slf4j packages that are not considered as user packages...
Will look into https://github.com/apache/mina-sshd

Looking again at @merks' analysis in #588 (comment) that should be the only trouble maker left in the SimRel. All other either only import org.slf4j (which is now exported in version 1.7.x and 2.0x) or have their version ranges already widened.

Let's hope we get a quick fix in sshd.

[HannesWell]

Hmm. Almost. Looks like sshd-osgi imports slf4j packages that are not considered as user packages...
Will look into https://github.com/apache/mina-sshd

Created a PR at MINA-SSHD to address it. Lets hope it is merged and released quickly:

• Adapt OSGi metadata of sshd.osgi to work with slf4j-api 1 and 2 apache/mina-sshd#336

[HannesWell]

Hmm. Almost. Looks like sshd-osgi imports slf4j packages that are not considered as user packages...
Will look into https://github.com/apache/mina-sshd

Created a PR at MINA-SSHD to address it. Lets hope it is merged and released quickly:

* https://github.com/apache/mina-sshd/pull/336

Good news. The PR is merged, so now we only have to wait for a release of the new version.

[HannesWell]

Hmm. Almost. Looks like sshd-osgi imports slf4j packages that are not considered as user packages...
Will look into https://github.com/apache/mina-sshd

Created a PR at MINA-SSHD to address it. Lets hope it is merged and released quickly:

* https://github.com/apache/mina-sshd/pull/336

Good news. The PR is merged, so now we only have to wait for a release of the new version.

Great. With a (self-assembeled) snapshot of mina-sshd 2.10.0 the platform-aggregator build finally succeeds.
So it looks like mina-sshd 2.10.0 is really the only missing piece. Let's hope the release in time for the next release 🤞🏽

[HannesWell]

With #1066 being merged, this is finally ready 😃🎉

[mickaelistria]

Thanks and congrats for this tedious improvement!