Issue #2285083 by crowdcg, andypost, larowlan: Rename contact category to contact form.

...fig_translation/src/Tests/ConfigTranslationListUiTest.php

.../config_translation/src/Tests/ConfigTranslationUiTest.php

.../modules/contact/config/install/contact.form.feedback.yml

.../modules/contact/config/install/contact.form.personal.yml

core/modules/contact/config/install/contact.settings.yml

core/modules/contact/config/schema/contact.schema.yml

core/modules/contact/contact.info.yml

core/modules/contact/contact.install

core/modules/contact/contact.links.action.yml

core/modules/contact/contact.links.menu.yml

core/modules/contact/contact.links.task.yml

core/modules/contact/contact.module

core/modules/contact/contact.routing.yml

core/modules/contact/src/ContactFormAccessControlHandler.php

core/modules/contact/src/ContactFormEditForm.php

core/modules/contact/src/ContactFormInterface.php

core/modules/contact/src/ContactFormListBuilder.php

core/modules/contact/src/Controller/ContactController.php

core/modules/contact/src/Entity/ContactForm.php

core/modules/contact/src/Entity/Message.php