feat: add Size interface for binaryset

[chyezh]

/kind improvement
issue: #585

[sre-ci-robot]

Welcome @chyezh! It looks like this is your first PR to zilliztech/knowhere 🎉

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.29%. Comparing base (3c46f4c) to head (bd7f0db).
Report is 61 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##           main     #586       +/-   ##
=========================================
+ Coverage      0   70.29%   +70.29%     
=========================================
  Files         0       67       +67     
  Lines         0     4720     +4720     
=========================================
+ Hits          0     3318     +3318     
- Misses        0     1402     +1402     

see 67 files with indirect coverage changes

[foxspy]

/lgtm

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chyezh, foxspy

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [foxspy]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.29%. Comparing base (3c46f4c) to head (bd7f0db).
Report is 62 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##           main     #586       +/-   ##
=========================================
+ Coverage      0   70.29%   +70.29%     
=========================================
  Files         0       67       +67     
  Lines         0     4720     +4720     
=========================================
+ Hits          0     3318     +3318     
- Misses        0     1402     +1402     

see 67 files with indirect coverage changes