replace comm_matrix helper functions with a CommutationMatrix and overloaded linalg ops

Cleanup Special Matrices code

* identifier() -> param_indices() (Dict{Symbol, Int})
* get_identifier_indices() -> param_to_indices() (Vector{Int})
* parameters -> params (Vector{Symbol})

convert() is a proper method to call to avoid unnecessary construction,
ctor semantics requires that a new object is constructed

make the type immutable

* use graph as a main parameter
* simplify rows processing
* don't reallocate table.columns

Co-authored-by: Maximilian-Stefan-Ernst <[email protected]>

because the ParTable contains rows and columns, it is not clear,
what sort() actually sorts.

Co-authored-by: Maximilian-Stefan-Ernst <[email protected]>

* use named tuples
* reduce code duplication
* use colnames vector instead of position_names Dict

* declare RAMConstant field types
* refactor constants collection to avoid code duplication

for clarity

* explicitly use Cholesky factorization

remove unnecesary arguments

by dispatching over optimizer

by dispatching over optimizer

no wrapper required

to reduce allocations

to reduce allocations

to avoid extra allocation

Co-authored-by: Maximilian Ernst <[email protected]>

Refactor objective/gradient/hessian evaluation

Devel

…lity

Release/v0.3.0

Add data simulation function

Devel