Fix Prometheus factory signature

[yurishkuro]

Resolves #3677

• adds `plugin.Configurable' validation to all factories to avoid re-introducing the bug
• remove error return value from Prometheus factory and log it as fatal inside the function, similar to all other factories

cc @albertteoh

[albertteoh]

LGTM, thanks.

[codecov]

Codecov Report

Merging #3681 (a839b57) into main (25558ac) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #3681   +/-   ##
=======================================
  Coverage   96.60%   96.60%           
=======================================
  Files         268      268           
  Lines       15715    15717    +2     
=======================================
+ Hits        15181    15183    +2     
  Misses        445      445           
  Partials       89       89           

Impacted Files	Coverage Δ
plugin/metrics/disabled/factory.go	100.00% <ø> (ø)
plugin/metrics/factory.go	100.00% <ø> (ø)
plugin/sampling/strategystore/adaptive/factory.go	100.00% <ø> (ø)
plugin/sampling/strategystore/factory.go	100.00% <ø> (ø)
plugin/sampling/strategystore/static/factory.go	83.33% <ø> (ø)
plugin/storage/badger/factory.go	95.80% <ø> (ø)
plugin/storage/cassandra/factory.go	97.08% <ø> (ø)
plugin/storage/es/factory.go	97.61% <ø> (ø)
plugin/storage/factory.go	98.39% <ø> (ø)
plugin/storage/grpc/factory.go	95.08% <ø> (ø)
... and 6 more

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