use IDEA certificate manager when connecting to the cluster (#600)

[adietish]

fixes #600

[adietish]

Current simplistic implementation is using the IDEA setting "Accept non-trusted certificates automatically". It tells our kubernetes-client to automatically accept all certificates if the setting is enabled in IDEA. It is very limited though:

1. The plugin cannot respect a change in this setting without the IDE being restarted. The reason for this is that the IDE wont notify the plugin of a change in this setting.
2. The plugin cannot take the certificates into account, that you manually add in the settings.

A solution to both these limitation would be to hand the IDEA certificate manager over to our kubernetes-client. This isn't possible currently because the client expect the certificate-manager and the key-manager. I need to get the ones used by the client, hand it over to IDEA and give the client the IDEA managers. The client currently wont allow me to access those, it looks as if I need a change in kubernetes-client for this.

[adietish]

If you follow the steps with our cluster bot, to reproduce this the plugin now behaves as follows:

You are prompted to accept or reject the untrusted certificate for your cluster:

Once you accept it you can deal with your cluster in IDEA

[adietish]

Hi @datho7561, can you please test this? You can find the steps to reproduce the issue and test this PR in #600 (comment). The variant 2, where you use the slack "Cluster Bot" is the simpler approach. There's no need to install a self-signed certificate since the cluster that the bot creates has a self-signed certificate already. Thanks!

[datho7561]

Looks good, and it's working well for me!

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.9% Duplication

[adietish]

Added unit-tests and javadoc.