rename zet_metric_timestamp structs to describe metric group scope

[matcabral]

the structure used to get the timestamp resolution and valid bits (zet_metric_global_timestamps_resolution_exp_t ) dos NOT have global scope. As the description says, the intention is to be used with zetMetricGroupGetProperties on a per metric group granularity. So, the fact that the structure is has global as part of the name and is listed under global timestamps section is confusing and out of scope. This struct is not meant to be used with the global APIs. So, I should be renamed

From:

• zet_metric_global_timestamps_resolution_exp_t
• ze_metric_global_timestamps_exp_version_t

To:

• zet_metric_group_timestamps_resolution_exp_t
• ze_metric_group_timestamps_exp_version_t