Use HTTP settings on beatsauth extension

[khushijain21]

Beatsauth extension now replaces the incoming round-tripper with beat's implementation of it.
The input to beatsauthextension is the entire http config block supported by beats - > Ref

How to test this PR

make genelasticcol

Create config.yaml and use the below config

receivers:
 filelog:
   include_file_name: true
   include:
     - "./otlp-all.json"

extensions:
 beatsauth:
   ssl:
    enabled: true
    verification_mode: none
   timeout: 9s
   
exporters:
 debug:
   verbosity: detailed
 elasticsearch:
  endpoints:
   -  https://localhost:9200
  password: testing
  user: admin
  auth:
   authenticator: beatsauth

service:
 extensions: [beatsauth]
 pipelines:
   logs:
     receivers: [filelog]
     processors: []
     exporters: [debug, elasticsearch]

./_build/elastic-collector-components --config config.yml

Relates elastic/elastic-agent#9633

[cmacknz]

Besides the cleanup of getHTTPOptions to make it clearer what we are omitting and why in the comments, this LGTM.