### What problem does this PR solve?
Feat: Add VariablePickerMenuPlugin to select variables in the prompt
text box by menu #4764
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Feat: The Begin and IterationStart operators cannot be deleted using
shortcut keys #4287
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Feat: Add the iteration Node #4242
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Yingfeng <yingfeng.zhang@gmail.com>
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
feat: Display input parameters on operator nodes #3240
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
feat: Add hint for operators, round to square, input variable, readable
operator ID. #3056
### Type of change
- [ ] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):
