The "create new variable" button does not appear when results match name of new variable

[tgdn]

Describe the bug
The "create new variable" button does not appear when results match name of new variable.

To Reproduce
Steps to reproduce the behavior:

1. Create a new Typebot
2. Open the variables drawer
3. Create a new variable "maet"
4. Attempt to create a new variable "ae"
5. Since the name of the variable "ae" matches "maet", it is impossible to create a new variable with the name "ae"

This is an issue because affiliate parameters may not be updated, and thus the name of the variable may not be chosen in advance.

⚠️ It is actually possible to press enter and create the variable, but it is IMHO not very user-friendly. It would make more sense to display the "+" button to click to create the variable.

Expected behavior
Render the "+" button to create a new variable whenever the user has typed something in the variable search input.