chore: rename functions

[binbin-li]

Description

What this PR does / why we need it:

Rename functions and options that are defined for creating store/verifier/policyEnforcer.
The previous names are in the form Create[xxx] or Create[xxx]Options, will be renamed to New[xxx] and New[xxx]Options to follow the golang naming convention.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

No tests required.

Checklist:

• Does the affected code have corresponding tests?
• Are the changes documented, not just with inline documentation, but also with conceptual documentation such as an overview of a new feature, or task-based documentation like a tutorial? Consider if this change should be announced on your project blog.
• Does this introduce breaking changes that would require an announcement or bumping the major version?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
policyenforcer.go	100.00% <100.00%> (ø)
store.go	100.00% <100.00%> (ø)
verifier.go	100.00% <100.00%> (ø)

[shizhMSFT]

LGTM. It is better to revise the PR description.

[junczhu]

LGTM

[susanshi]

Thanks for the updates.