Define profiling signals using weaver

[thompson-tomo]

Is your feature request related to a problem? Please describe.
Weaver lacks any ability to define profiles

Describe the solution you'd like

We should be able to define profile telemetry using yaml.

Based on the proto I forsee the following definitions as being need.

the profile definition should contain:

• period_kind: string ie heap
• period_unit: string ie bytes
• attributes: attribute ref array
• sample: sample ref

The sample definition should contain:

• sample_kind: string ie allocated_space
• sample_unit: string ie bytes
• attributes: attribute ref array

Which when resolved creates the following definition:

• period_kind: string ie heap
• period_unit: string ie bytes
• sample_type: string
• sample_kind: string ie allocated_space
• sample_unit: string ie bytes
• attributes: attribute array with the capture.level property distinguishing if it is sample or profile attribute as per Instrumentation scopes #1005

Describe alternatives you've considered
Not defining profiles.

Directly defining profiles in their resolved form ie no seperate samples but samples couldn't be re-used.

Additional context
Should be considered in context of v2 to ensure it is designed to support it.

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