default pipeline,task and finally timeouts

[flokain]

Feature request

refactor default-timeout-minutes to the following parameters in config-defaults.

default-timeout-pipeline-minutes: "40"  
default-timeout-tasks-minutes: "40"  
default-timeout-finally-minutes: "20"

timeouts:
  pipeline: "0h0m60s"
  tasks: "0h0m40s"
  finally: "0h0m20s"

Use case

To be sure that by default finally sections get a chance to run on a pipelinerun timeout. Currently we have to set this on EVERY Pipelinerun. I would be neat to set this as default and override it, on pipelineRuns where we do not want to have it.

Also it would streamline the configuration options, as it is available in pipelineruns already.