Process semconv: define common attributes and revisit requirement levels

[lmolkova]

Area(s)

area:process

Is your change request related to a problem? Please describe.

We require any of the following attributes to be present

semantic-conventions/docs/resource/process.md

Lines 39 to 45 in a04a1f4

	**Additional attribute requirements:** At least one of the following sets of attributes is required:
	* [`process.executable.name`](../attributes-registry/process.md)
	* [`process.executable.path`](../attributes-registry/process.md)
	* [`process.command`](../attributes-registry/process.md)
	* [`process.command_line`](../attributes-registry/process.md)
	* [`process.command_args`](../attributes-registry/process.md)

As a result, users would get inconsistent data from different systems and instrumentations.
Vendors will need to know how to parse and extract specific details (such as process name).

Describe the solution you'd like

The approach we follow in HTTP and other semconv:

• Find 1-2 required attributes (e.g. process.executable.name) which are available everywhere
• Require instrumentations to do the parsing/extraction of this common information so that users and consumers would get consistent data
• Set appropriate requirement levels on other attributes

[ChrsMark]

cc: @open-telemetry/semconv-system-approvers