Edit a TikTok campaign

Changes a TikTok campaign's name or budget. The budget is a decimal in the account currency. Use when: renaming for clarity, or the user has decided to scale a campaign and named the amount. Do not use it to pause or resume — tiktok_pause_campaign and tiktok_resume_campaign exist so the risk of that change is stated correctly before the user approves it. Do not use it for dates: a TikTok campaign has no schedule of its own, so start_date and end_date are refused here — set them on each ad group with tiktok_update_ad_group. Do not change a budget by more than about 30% at a time. TikTok treats a large jump as a new learning phase and the CPA gets worse for a few days before it settles; the tool warns when a change crosses that line, and the warning is worth repeating to the user. Do not set a budget here when the campaign uses BUDGET_MODE_INFINITE: the ad groups hold the budget and this tool will refuse, because capping the campaign would throttle every ad group at once. TikTok also refuses a new budget below 105% of what the campaign has already spent today (lifetime, for a lifetime budget); the tool checks that first. Returns the campaign read back from TikTok after the change, so the new values are confirmed rather than assumed. At least one of name or daily_budget must be given. If the user says "increase the budget" without a number, ask how much. Never pick an amount for them.