Fix zero dimensional BlockArray and BlockedArray

[ogauthe]

Fixes #409 and add tests.

BlockArrays are now fine, however BlockedArray are still broken. This is due to the type piracy on view mentioned in #409. I do not see how to fix it at the moment.

[ogauthe]

I implemented @dlfivefifty suggestions to fix unsafe_views type piracy. I also fixed several other issues, I hope I did not forget any standard use. unsafe_views aside, all other changes only affect zero-dimensional arrays and the main cases are unaffected.

[ogauthe]

For a zero-dimensional Array, .* and .^ return a scalar. This is a bit surprising, but it matches the behavior of Array so I think it is acceptable.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.66%. Comparing base (68cffad) to head (a5d3cc4).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #410      +/-   ##
==========================================
+ Coverage   96.25%   96.66%   +0.41%     
==========================================
  Files          18       18              
  Lines        1628     1649      +21     
==========================================
+ Hits         1567     1594      +27     
+ Misses         61       55       -6     

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[dlfivefifty]

Can you get the codecov up?

downstream failure looks spurious

[ogauthe]

Should be fine now. Also realized reshape was broken.

[jishnub]

This PR seems to add many methods. Do we really need them all? E.g. the Array constructor fails because of the ambiguity in view, so would resolving this get the constructor working without the need to add a specialized method?

[ogauthe]

I double checked, there were 3 changes that were not necessary. Reverting any other change breaks the tests.