Implement new Service method to retrieve its SID type info

[PaulDance]

Dear maintainers,

The Service struct supports modifying the underlying system resource's SID type information through the Service::set_config_service_sid_info method. However, there is currently no way to easily retrieve the value from the service manager, for example to check if a call to set_config_service_sid_info actually worked.

This PR therefore adds a new small Service::get_config_service_sid_info method that does just that. Also, some other minor bonus changes are included.

Cheers,
Paul.

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This change is 

[dlon]

Reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @PaulDance)

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src/service.rs line 1652 at r1 (raw file):

    /// access permission prior to calling this method.
    pub fn get_config_service_sid_info(&self) -> crate::Result<ServiceSidType> {
        let mut data = vec![0u8; u32::BITS as usize / 8];

Nit: This could probably be replaced with let mut data = 0u32;

[dlon]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @PaulDance)

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src/service.rs line 1652 at r1 (raw file):

Previously, dlon (David Lönnhager) wrote…

Nit: This could probably be replaced with let mut data = 0u32;

Or even better: ServiceSidType::None

[dlon]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @PaulDance)

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src/service.rs line 1652 at r1 (raw file):

Previously, dlon (David Lönnhager) wrote…

Or even better: ServiceSidType::None

My bad, I see now that it must be a mutable slice. I must have been looking at change_config2.

[PaulDance]

Yes, indeed!

Thanks a bunch!