Provide sidecar-less model

[vzhukovs]

Current changes proposal provides sidecar-less mode according to eclipse-che/che#20863

Main highlights from the current proposed changes:

• refactored Dockerfile by moving environment configuration from runtime image to builder image
• builder image is based on the ubi8 instead of ubi8-minimal
• removed install-platform-dependencies.sh and moved the code to the builder image
• added runtime argument nosplash
• added sh script which copies the configured editor to another runtime image by mounting a shared volume
• added sh script which runs the configured editor in another runtime image
• reworked runtime user configuration

Signed-off-by: Vladyslav Zhukovskyi vzhukovs@redhat.com

[benoitf]

Hello, from where come these environment variables ?

[vzhukovs]

Hi! They come from devfile: https://github.com/vzhukovs/che-idea/blob/main/.che/che-editor.yaml#L52-L55