Add `symoroutils/symbolmgr.py` file
Update `Symoro` with `SymbolManager`

Rename `Symoro` class to `SymbolManager` and place it in
`symoroutils/symbolmgr.py`.
Update in all places to call `SymbolManager` instead of `Symoro`.
Add `symoroutils/tools.py`

Move functions from `pysymoro/symoro.py` to `symoroutils/tools.py`.
These functions are helper functions that are called by other modules.
Fix `NameError` from function calls

Fix `NameError` arising from different function calls in
`symoroutils/symbolmgr.py` and `symoroutils/tools.py`.
Add `symoroutils/dyninit.py`
Move initialisation class to new file

Move initialisation class to `symoroutils/paramsinit.py`.
Rename class `Init` to `ParamsInit`.
Rename `symoroutils/dyninit.py` to `symoroutils/paramsinit.py`.
Update to call `ParamsInit` class instead in all relevant parts.
Minor changes in `symoroutils/symbolmgr.py`