Add tools to list dispatcher specializations

[Ericgig]

Description
Add a function that list all dispatched functions and their specialization.
It automatically adapt to new data-layer and dispatched functions.
Only show pure specialization: solve[Dense, Dense] not solve[CSR, Dense].

I also register 2 specializations that were created, but not registered.

Example:

>>> from qutip.core.data.dev_utils import specialisation_table
>>> specialisation_table()

Output only specialisation
|Dispatched function | JaxArray |   CSR    |  Dense   |
|zeros               |   True   |   True   |   True   |
|identity            |   True   |   True   |   True   |
|diag                |   True   |   True   |   True   |
|one_element         |   True   |   True   |   True   |
...
Binary specialisation
|Dispatched function | JaxArray |   CSR    |  Dense   |
|add                 |   True   |   True   |   True   |
|sub                 |   True   |   True   |   True   |
|matmul              |   True   |   True   |   True   |
|multiply            |   True   |   True   |   True   |
|kron                |   True   |   True   |   True   |
|solve               |  False   |  False   |   True   |
...

This could also go into a notebook if it fit better there.

[coveralls]

Coverage: 75.328%. Remained the same when pulling 585435c on Ericgig:dev.spec_table into 775cdcc on qutip:master.

[hodgestar]

I don't think we should skip the dev tools in coverage. It's always good to know what code is being covered by tests, even if we decide not to cover them.

Aside: I also think that tests should be included in coverage. I've often picked up issues where a test or part of a test isn't being run by looking at coverage (e.g. the test is skipped if a dependency isn't installed and no test runner instance has that dependency).

[hodgestar]

Having some helpers for examining the dispatcher tree seems like a good idea and you already found some missed specializations using them.

I don't have a strong opinion on what these tools should look like yet, so very happy with these.

I would prefer to have a couple of simple tests for the two top-level functions just to be sure we don't accidentally break them if we tweak the data layer.

[Ericgig]

I just cleaned up a tool I used when making the jax data layer, but I don't want to add something that will ask for our time to maintain, thus no test or coverage.

In this meaning, it doesn't seems belong here.

I am closing this and making a new one with just the missing specializations + will check if they were also skipped in test.