Reorganize repo

[max-radin]

As discussed in the last GSEE meeting, we'd like to reorganize the directories to make content easier to access and maintain. In particular, we'd like to consolidate some of the top level directories and move the bulk of the python code into the src directory so that it is part of a package.

• The new high-level directory structure should like more or less like what was discussed at the meeting (shown below).
• Most of the business logic should be moved to src so that it is part of the python package. Ideally the scripts themselves will be short python files that just parse command-line arguments and then just call a few functions from the package. The one exception is code that is specific to an example solver, which can live in the appropriate subdirectory of examples.
• We should make sure that the scripts still work after the migration, and in particular check if any paths need to be updated.
• We should also make sure to update any paths that appear in README files.
• We should avoid scope creep in this reorganization. The intention is just to move things into sensible directories, not to write a bunch of code.

qb-gsee-benchmark
├── data
│   ├── solutions
│   ├── problems_instance
│   ├── performance_metrics
│   ├── json_files_with_errors
│   └── features
├── schemas
├── examples
│   ├── dmrg_2024
│   ├── df_qpe_2024
│   └── performance_analysis
├── src
├── scripts
└── tests