[FEATURE] Adjust ButtonView to allow for customization for the brackets

**Is your feature request related to a problem? Please describe.** A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] I would like to change what character the buttons use instead of the default "<" and ">". **Describe the solution you'd like** A clear and concise description of what you want to happen. I would the brackets to be a settable value in the struct. **Describe alternatives you've considered** A clear and concise description of any alternative solutions or features you've considered. I am too new at Rust and I'm worried if I make a pull request it will be the least efficient way possible to do this. **Additional context** Add any other context or screenshots about the feature request here. Thank you for taking the time to read this.