Separate base images for job execution

Multiple services in YT run in vanilla operations (CHYT, SPYT, DQ). Some of them have non-trivial dependencies, such as the requests library in [clickhouse-trampoline](https://github.com/ytsaurus/ytsaurus/blob/main/yt/chyt/trampoline/clickhouse-trampoline.py#L12). So far we have been lucky for binaries to be mostly self-contained/packages to be installed somehow.

As a proper solution, we should introduce a base execution image, which will contain all necessary dependencies **and** be much smaller than the exec node image that is used by default: there is no need for ytserver binaries in job containers.

This image will then need to be passed along to controllers of vanilla operations, mostly strawberry (and maybe YQL agent).