Fix logging early errors from goroutines and panic with custom Kubeconfig

[pkosiec]

Description

Changes proposed in this pull request:

• Always log early errors from goroutines
• Ensure Cloud Slack doesn't return error on exiting Botkube OS
• Fix panic when using custom Kubeconfig
• Ensure Botkube dev version is valid Semver one (for dev purpose when used with remote config)

Testing

You can try to add an error in one of goroutines and see if it is properly logged. For example, with Cloud Slack invalid auth:

INFO[2023-06-13T13:19:08+02:00] Skipping waiting for Config Watcher sync...   component="Config Watcher Sync"
INFO[2023-06-13T13:19:08+02:00] Starting...                                   component="Config Updater"
INFO[2023-06-13T13:19:08+02:00] Shutdown requested. Finishing...              component="Health server"
INFO[2023-06-13T13:19:08+02:00] Shutdown requested. Finishing...              component="Config Updater"
INFO[2023-06-13T13:19:08+02:00] Shutdown requested. Finishing...              component="Metrics server"
INFO[2023-06-13T13:19:08+02:00] plugin process exited                         path=/tmp/botkube/source_v0.0.0-latest_kubernetes pid=19261 plugin=botkube/kubernetes
INFO[2023-06-13T13:19:08+02:00] plugin process exited                         path=/tmp/botkube/executor_v0.0.0-latest_kubectl pid=19260 plugin=botkube/kubectl
DEBU[2023-06-13T13:19:08+02:00] Reporting...                                  component=GraphQLStatusReporter deploymentID=074e325a-0dc7-4c9f-8d35-879ee5df4196 resourceVersion=40 type=failure
DEBU[2023-06-13T13:19:09+02:00] Reporting successful.                         component=GraphQLStatusReporter deploymentID=074e325a-0dc7-4c9f-8d35-879ee5df4196 resourceVersion=40 type=failure
ERRO[2023-06-13T13:19:09+02:00] while waiting for goroutines to finish gracefully: while receiving cloud slack events: rpc error: code = Unknown desc = invalid API key
2023/06/13 13:19:09 while sending initial help message: while getting the help data: while getting the Config Map: Get "https://35.185.103.213/api/v1/namespaces/botkube/configmaps/botkube-system": context canceled
exit status 1

[josefkarasek]

lgtm 👍