#8961: add @ts-ignore to the lines before an unused import or value is or might be

Created by: sdoeringNew

fix #8961

Generated typescript files for the generators typescript-fetch do not compile with activated type-checks in typescript. There are plenty of errors like:

error TS6133: 'petDiscriminator' is declared but its value is never read.
error TS6192: All imports in import declaration are unused.

As it is very hard to distinguish between used and unused imports and values, a // @ts-ignore is added to every line before such error appears or might appear.

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package 
  ./bin/generate-samples.sh
  # ./bin/utils/export_docs_generators.sh # no docs changed

• Commit all changed files. This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master. These must match the expectations made by your contribution. You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
• For Windows users, please run the script in Git BASH. # No Windows user
• File the PR against the correct branch: master (5.3.0), 6.0.x
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

I welcome the technical committee: @TiFu @taxpon @sebastianhaas @kenisteward @Vrolijkx @macjohnny @topce @akehir @petejohansonxo @amakhrov