Restructuring the class structure

[mk3008]

After completing the demonstration experiment, it was confirmed that there is practicality, so we will review the structure once.

Here are some ideas for revision:

• Separate the model structure of SQL itself and the Parser and Builder projects.
• Integrate classes with overlapping uses.
• Compatibility is emphasized, but structural optimization is prioritized over compatibility.

[mk3008]

Made another project
https://github.com/mk3008/Carbunql