Fix blockbloom in header error

[thomas-nguy]

Closes: #248

Description

When blockbloom is nil and empty it is currently returning an error. We should return an empty bloom instead to avoid breaking other functionnalities.

Note that I have notice a weird behavior with the context (which return a blockboom at currentheight-1 when context is set at current height but it cannot be found is context is set at current height -1

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[fedekunze]

see #263, that should fix the issue

[thomas-nguy]

I have checked on main (including #263) but the issue is still there.

It is working if I always use ctx's height = height +1 . Not sure why it is happening. I will need to investigate further

[fedekunze]

few requests for comments. Make sure you pull the latest changes from main

[fedekunze]

ACK, can you add a bugfix changelog entry?

[thomas-nguy]

sure, README updated

[codecov]

Codecov Report

Merging #258 (9763cc0) into main (e09bf23) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #258      +/-   ##
==========================================
- Coverage   47.55%   47.54%   -0.02%     
==========================================
  Files          45       45              
  Lines        3135     3136       +1     
==========================================
  Hits         1491     1491              
- Misses       1569     1570       +1     
  Partials       75       75              

Impacted Files	Coverage Δ
x/evm/keeper/state_transition.go	0.00% <0.00%> (ø)