Add singleton flags to factories and standardize attributes

[djaglowski]

This PR is an extension of #11344 that addresses #11814.

Major changes:

• Add a Metadata() method to receiver.Factory, exporter.Factory and connector.Factory (processor.Factory excluded intentionally as described in Loggers for shared components should not report signal type. #11814). These Metadata() methods return Metadata structs, which act similarly to consumer.Capabilities in that they are intended as a set of information which describes the components which the factory produces.
• Remodels each component's as a proper go.opentelemetry.io/otel/attribute.Set. This set is used as the ID in the graph, but also as the set of attributes that creates the logger. In the future, the set will be automatically used to describe other aspects of the collector's own telemetry.
• The logger fields are changed to match those described in the component telemetry RFC.

Minor changes:

• Unknown component types are detected earlier in the startup process. (When the graph is being assembled, rather than when the components of the graph are being instantiated.) This is necessary so that we can obtain the Metadata from the appropriate factory. There is a minor user facing change in that the error message is not wrapped in a "could not build" prefix. I moved the processors to this pattern as well in order to match the other components.

[djaglowski]

If desired, I believe I can split this PR into several smaller PRs. However, I wanted to put this version up in order to show the overall picture.

[codecov]

Codecov Report

Attention: Patch coverage is 89.75904% with 17 lines in your changes missing coverage. Please review.

Project coverage is 91.64%. Comparing base (0ece678) to head (79e1bcb).

Files with missing lines	Patch %	Lines
exporter/xexporter/exporter.go	0.00%	4 Missing ⚠️
receiver/xreceiver/profiles.go	0.00%	4 Missing ⚠️
service/internal/graph/connector.go	66.66%	1 Missing and 2 partials ⚠️
service/internal/graph/exporter.go	66.66%	1 Missing and 2 partials ⚠️
service/internal/graph/receiver.go	66.66%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #12057      +/-   ##
==========================================
- Coverage   91.67%   91.64%   -0.04%     
==========================================
  Files         455      454       -1     
  Lines       24038    24139     +101     
==========================================
+ Hits        22037    22121      +84     
- Misses       1629     1640      +11     
- Partials      372      378       +6     

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