Fix 2d coordinate interpolation

[w-k-jones]

Fixes the problem with 2d coordinate interpolation producing object dtypes in feature_detection raised in #240 that was the cause of the bug in #239

Ideally this could be released as part of v1.4.2, but the changes to the utils structure as part of v1.5 make it impractical to separate

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[codecov]

Codecov Report

Base: 47.15% // Head: 47.15% // No change to project coverage 👍

Coverage data is based on head (b78f1e0) compared to base (ce390a3).
Patch coverage: 50.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           RC_v1.5.0     #250   +/-   ##
==========================================
  Coverage      47.15%   47.15%           
==========================================
  Files             14       14           
  Lines           2704     2704           
==========================================
  Hits            1275     1275           
  Misses          1429     1429           

Flag	Coverage Δ
unittests	47.15% <50.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
tobac/utils/general.py	69.80% <50.00%> (ø)

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[JuliaKukulies]

Looks good. Yes true, it will be a bit of a pain to merge this back to v1.5 with the utils module split. However, I think we should go for it nonetheless, since it makes sense to include this in v1.4.2 as you say

[freemansw1]

I'm happy with this, thanks for the bugfix! I agree that 1.4.2 would be better but I'm happy to wait until 1.5.0 if it's a pain. 1.5.0 in theory shouldn't be far behind.

[freemansw1]

Once #251 is merged, I think this PR can be closed, right?

[w-k-jones]

I don't think the changes got moved across to the v1.5 branch due to the change in the utils submodule structure, so I'll wait until #257 is merged and then see if this can be closed or merged

[freemansw1]

Yeah, good point @w-k-jones! Let's get this merged (after #257).

[JuliaKukulies]

#257 merged, good to go!