Enter text in text_sensor component via web component

**Describe the problem you have/What new integration you would like**
If using esphome stand-alone there is sometimes a need to enter configuration data such as api keys. A text_sensor component rendered as a text input box in the web gui would be perfect.

**Please describe your use case for this integration and alternatives you've tried:**
Imagine an esphome with a generic config, connected to Wi-Fi and a temp sensor and reporting temp to a remote server.
When starting the device for the first time the captive portal will enable the user to enter Wi-Fi config.
The the user can surf to the device an enter some config like API-key to remote site in a text input box in the web gui.

**Additional context**