timeouts for promotions: setup default and allow the user to override

[enekofb]

during promotions, for example, pull request promotions, we have operations that might be expensive in terms of time,
for example, cloning a configuration repo would depend on the size of the repo

In order to control this scenario, we would like tohave default timeout for the promotion execution and the ability to of the user to override this value within the pipeline CR

AC

• define the timeout strategy for pipeline promotions
• implement providing a default and user-specific override

[LappleApple]

From @yitsushi: "Right now with all our demo stuff it's happy, but as soon as it hits heavy load it may [have problems] handling long running processes without expected timeout. It can hurt on mono-repos with a lot of changes (I don't know if we shallow clone or full clone, I hope shallow)"

[LappleApple]

To revisit after Pipelines 2.0 work.