Use default devfile during workspace startup based on 'ssh://' if devfile can not be retrieved by che-server

[ibuziuk]

Is your enhancement related to a problem? Please describe

PR with initial SSH support implementation - eclipse-che/che-server#539
There are a few enhancements that need to be done as part of this issue:

• if SSH URL points to the unsupported provider and che-server can not retrieve devfile, workspace should be started based on the default one (appropriate warning message should be shown on the workspace startup screen)
• default devfile should be also used if SSH url points to the supported provider, but devfile still can not be retrieved (e.g. private repo, no OAuth / PAT are configured)

Describe the solution you'd like

N/A

Describe alternatives you've considered

No response

Additional context

Related issue - #22473

[ibuziuk]

@vinokurig @l0rd please, review
this is a follow up issue based on the comments from eclipse-che/che-server#539
I think we can close #22473 in favour of this issue

[l0rd]

@vinokurig @l0rd please, review this is a follow up issue based on the comments from eclipse-che/che-server#539 I think we can close #22473 in favour of this issue

LGTM

[ibuziuk]

@vinokurig please, make sure that the fixes are backported for 3.9

[vinokurig]

checrry-picked to 7.74 d8991eafd1a49aec704fe618834d1d5e99eb6883

[nickboldt]

Tracked downstream in https://issues.redhat.com/browse/CRW-4871

[ibuziuk]

closing as done