Add GraphQL setter to GraphqlServiceBuilder

[minwoox]

Motivation: A user might want to set GraphQL directly to the GraphqlServiceBuilder which could be shared between Expedia GraphQLRequestHandler and Armeria's GraphqlService.

Modification:

• Add the setter method for GraphQL.

Result:

• You can now set GraphQL to the GraphqlServiceBuilder.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 63.01370% with 27 lines in your changes are missing coverage. Please review.

Project coverage is 73.91%. Comparing base (14c5566) to head (62372a1). Report is 13 commits behind head on main.

:exclamation: Current head 62372a1 differs from pull request most recent head 10db64f

Please upload reports for the commit 10db64f to get more accurate results.

Files	Patch %	Lines
.../armeria/server/graphql/GraphqlServiceBuilder.java	63.01%	9 Missing and 18 partials :warning:

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5269      +/-   ##
============================================
- Coverage     74.05%   73.91%   -0.14%     
+ Complexity    21253    20082    -1171     
============================================
  Files          1850     1728     -122     
  Lines         78600    74113    -4487     
  Branches      10032     9457     -575     
============================================
- Hits          58209    54784    -3425     
+ Misses        15686    14837     -849     
+ Partials       4705     4492     -213     

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[github-actions[bot]]

🔍 Build Scan® (commit: 10db64f2f6e630f3e230abdb93052d17b1033505)

Job name	Status	Build Scan®
build-windows-latest-jdk-21	✅	https://ge.armeria.dev/s/t3mgmngtmpcra
build-self-hosted-unsafe-jdk-8	✅	https://ge.armeria.dev/s/alhcanaqxdsie
build-self-hosted-unsafe-jdk-21-snapshot-blockhound	✅	https://ge.armeria.dev/s/nsw2ftxqqvklm
build-self-hosted-unsafe-jdk-17-min-java-17-coverage	✅	https://ge.armeria.dev/s/qi6vlrsmrvm4w
build-self-hosted-unsafe-jdk-17-min-java-11	✅	https://ge.armeria.dev/s/5kjhic5azn5pq
build-self-hosted-unsafe-jdk-17-leak	✅	https://ge.armeria.dev/s/zonqj5olph4es
build-self-hosted-unsafe-jdk-11	✅	https://ge.armeria.dev/s/bjcq3nfaumgho
build-macos-12-jdk-21	✅	https://ge.armeria.dev/s/s5wxsmktmcqcu