integrating takeover API in all bucket layers

[anushka567]

Description

Adding CreateAppendableObjectWriter method to all bucket interfaces , to implement the takeover support for appendable unfinalized objects in ZB. Ref: link
Implementation and tests will be included in a follow-up PR.

Link to the issue in case of a bug fix.

b/415727697

Testing details

1. Manual - Manually testing of different flows - No breakage.
2. Unit tests - NA
3. Integration tests - NA

Any backward incompatible change? If so, please explain.

[codecov]

Codecov Report

Attention: Patch coverage is 3.33333% with 58 lines in your changes missing coverage. Please review.

Project coverage is 78.62%. Comparing base (22649eb) to head (47cd91a).
Report is 12 commits behind head on master.

Files with missing lines	Patch %	Lines
internal/gcsx/prefix_bucket.go	0.00%	11 Missing ⚠️
internal/ratelimit/throttled_bucket.go	0.00%	9 Missing ⚠️
internal/gcsx/content_type_bucket.go	0.00%	6 Missing ⚠️
internal/storage/debug_bucket.go	0.00%	6 Missing ⚠️
internal/storage/mock/testify_mock_bucket.go	0.00%	6 Missing ⚠️
internal/storage/testify_mock_bucket.go	0.00%	6 Missing ⚠️
internal/monitor/bucket.go	0.00%	5 Missing ⚠️
internal/storage/fake/bucket.go	0.00%	3 Missing ⚠️
internal/storage/mock_bucket.go	0.00%	3 Missing ⚠️
internal/storage/caching/fast_stat_bucket.go	0.00%	2 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3268      +/-   ##
==========================================
+ Coverage   78.51%   78.62%   +0.10%     
==========================================
  Files         128      129       +1     
  Lines       17657    17831     +174     
==========================================
+ Hits        13863    14019     +156     
- Misses       3331     3349      +18     
  Partials      463      463              

Flag	Coverage Δ
unittests	78.62% <3.33%> (+0.10%)	⬆️

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[vadlakondaswetha]

why do we need storage.AppendableWriterOpts as seperate argument?

[anushka567]

Updated the method definition to avoid using this argument directly.