Add Cypress plugin for linter

https://typescript-eslint.io/rules/no-require-imports/
There was a complaint from ESLint about the use of require in the `cypress.config.ts` file.

There is a Cypress plugin for ESLint https://github.com/cypress-io/eslint-plugin-cypress and this approach to adding it to the `.eslintrc.json` is suggested in the history of the project. The project claims you need to be using ESLint 9 or greater, which we probably should look into, and it might mean that this plugin would need to be updated manually in that migration process. I have a PR for that migration as well:
#1664

client/.eslintrc.json

@@ -6,6 +6,8 @@
       "files": ["*.ts"],
       "extends": [
         "eslint:recommended",
+        // This helps the linter deal more kindly with the Cypress configuration file `cypress.config.ts`
+        "plugin:cypress/recommended",
         "plugin:@typescript-eslint/recommended",
         "plugin:@angular-eslint/recommended",
         // This is required if you use inline templates in Components