slurm plug-in: remove --cpus-per-task requirement

[AnarManafov]

DDS slurm plug-in sets the --cpus-per-task= to the number of task slots per agent.
That was intently made to prevent users from overbooking resources on slurm.

Looks like this is not always convenient, according to ALICE pre-production tests.
This requirement should be either configurable (enabled by an option in dds submit) or completely removed.

I lean to the configurable solution.
dds-submit and its ToolsAPI should accept an "--enable-overbooking" argument, which will instruct plug-in to disable --cpus-per-task (for slurm) and similar arguments in other RMS plug-ins. When specified, the responsibility to define cpu requirements will be delegated to the user.

[rbx]

Would it be reasonable to configure --cpus-per-task via a submit request option:

dds::tools_api::SSubmitRequest::request_t requestInfo;
requestInfo.m_cores = 10;

?
If the option is not provided, then you can put a default of your choice, or none.

[AnarManafov]

@rbx , this is the plan. I don’t want to give up on this protection.
At the moment it’s removed only temporarily to avoid blocking of Alice.

[AnarManafov]

@rbx , the feature is implemented in the master.
Now, dds submit (command and ToolsAPI) support flags.
The #SBATCH --cpus-per-task=%DDS_NSLOTS% requirement can be disabled by providing the "enable-overbooking" flag (ToolsAPI or dds-submit).
API example:

SSubmitRequest::request_t requestInfo;
...
// Set flags
requestInfo.setFlag(dds::tools_api::SSubmitRequestData::ESubmitRequestFlags::enable_overbooking,
                                   <state of the flag: true/false>);
...

Please note, by default the flag is off. That means ODC needs to enable it for ALL alice partitions, except the ones which need a CPU-based allocation.
This is very important as ALICE doesn't use CPU requirement for most of their runs. They mostly use overbooking on nodes.