Revert adding a callback to the Encoder

[SupunS]

Related to https://github.com/dapperlabs/cadence-private-issues/issues/64

Depends on https://github.com/onflow/atree/pull/290

Description

Reverts #287. The original requirement of knowing the size of the slabs to be encoded can be achieved using https://github.com/onflow/atree/pull/290

---

• [ ] Targeted PR against main branch
• [x] Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• [x] Code follows the standards mentioned here
• [x] Updated relevant documentation
• [x] Re-reviewed Files changed in the Github PR explorer
• [x] Added appropriate labels

[codecov-commenter]

Codecov Report

Merging #291 (f2d7eb9) into main (82ce4cc) will decrease coverage by 0.07%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #291      +/-   ##
==========================================
- Coverage   69.16%   69.10%   -0.07%     
==========================================
  Files          14       14              
  Lines        7319     7314       -5     
==========================================
- Hits         5062     5054       -8     
- Misses       1625     1627       +2     
- Partials      632      633       +1     

Impacted Files	Coverage Δ
encode.go	80.64% <ø> (ø)
array_debug.go	54.16% <100.00%> (ø)
basicarray.go	53.55% <100.00%> (ø)
map_debug.go	55.50% <100.00%> (ø)
storable.go	65.57% <100.00%> (-2.61%)	:arrow_down:
storage.go	79.41% <100.00%> (-0.52%)	:arrow_down:

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.