Switch Case Algorithm

**Describe the problem you have/What new integration you would like**
I like to code for a ESP a user menu, usualy this is done with a switch-case-loop which is not available via ESPHome, neither the variables which would allow to store a string.

**Please describe your use case for this integration and alternatives you've tried:**
I intend to build a watering device which switch on various tabs to rain te garden, bedie a fix program coded, I need ability to overwrite via some buttons on the device

**Additional context**
I know libraries could be added in principle, but here we have base functionality in C++, hence no idea on how to make this functionality available.

Start by reviewing ESPHome's existing C++ base functionality and the approach used for adding libraries. Define how switch-case behavior and string storage would be exposed for the ESP watering-device use case, then verify that the proposed integration supports button-driven overrides alongside a fixed program.

Written by the indexing model from the issue text.