Use equality instead of identity to compare types

[tpoliaw]

In some cases, possibly when MsgGenerator is defined or imported from
different modules, the types can be equivalent but are not the same
instance. In these cases, the identity check would fail and some plans
would be excluded where they shouldn't be. Using equality checks instead
mean it shouldn't matter where the MsgGenerator type was defined as all
instances should be equal.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.10%. Comparing base (2783092) to head (0424e70).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #533   +/-   ##
=======================================
  Coverage   91.10%   91.10%           
=======================================
  Files          40       40           
  Lines        1787     1787           
=======================================
  Hits         1628     1628           
  Misses        159      159           

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[tpoliaw]

copied from the Jira ticket

RE the acceptance criteria, I don't think the imports need to be changed. I could add tests to check that functions defined with both versions of MsgGenerator are included but given in some cases, the different imports still resolve to the same type, I'm not sure they're going to actually test the failure case.

[callumforrester]

Thanks for looking at this!

[DiamondJoseph]

This issue is now extending to equality when deployed on i22.

In [25]: for obj in load_module_all(mod):
    ...:         print(f"{obj.__annotations__['return']}")
    ...: 
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]
collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]

In [26]: from dodal.common import MsgGenerator as m1

In [27]: m1
Out[27]: collections.abc.Generator[bluesky.utils.Msg, typing.Any, None]

In [28]: from dls_bluesky_core.core import MsgGenerator as m2

In [29]: m2
Out[29]: typing.Generator[bluesky.utils.Msg, typing.Any, NoneType]

In [30]: for obj in load_module_all(mod):
    ...:         print(f"{obj.__annotations__['return'] == m2}")
    ...: 
False
False
False
False
False
False
False
False

In [31]: for obj in load_module_all(mod):
    ...:         print(f"{obj.__annotations__['return'] == m1}")
    ...: 
True
True
True
True
True
True
True
True

In [32]: