feat: adjust wording on campaign type selection screen

[tackley]

None of our ad formats are sub-premium, so this wording is misleading.

[github-actions]

[puLL-Merge] - brave/ads-ui@1196

Here is my review of the PR:

Description

This PR makes a few minor text changes in the localization files and validation schema. It changes some instances of "premium ad placements" to "New Tab Takeover campaigns". A few validation rules around audience targeting and location fields were removed or commented out.

Changes

Changes

auth/registration/AccountChoice.tsx

• Changed "premium ad placements" to "New Tab Takeover campaigns" in the contact us link text

locales/en.po, es.po, pt.po, test.po

• Updated translations for the "New Tab Takeover campaigns" text change
• Removed translations for a few validation messages that were removed

validation/CampaignSchema.tsx

• Removed "At least one audience must be targeted" validation
• Commented out the "Location" field and its description text
• Adjusted line numbers for other validations due to removed lines

user/campaignList/CampaignList.tsx
user/views/user/search/SetupProgress.tsx
user/ads/AdsExistingAd.tsx

• Line number changes only due to changes in other files

components/Creatives/SearchPreview.tsx

• Line number change on "Sponsored" text, likely due to unrelated changes in this file

Overall this PR focuses on changing the wording around premium ad placements and removes a couple targeting related validations. The changes look straightforward and low-risk.