Update case used on some QA selectors

What does this MR do and why?

Looking into introducing a cop to enforce the case used on QA page object elements - !129733

It was noted that several elements are using snake_case rather than kebab-case. This MR updates those where possible. Others are dynamic symbols that will require exclusions in the cop MR.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

How to set up and validate locally

Run affected feature specs:

bundle exec rspec spec/helpers/sidebars_helper_spec.rb

qa/ bundle exec rspec -O .rspec_internal spec/page/base_spec.rb

Ensure the test pipeline E2E test Allure report either reports all passes - OR any failures are unrelated and known. I will add a comment to the allure report stating such.