Add client methods

[cmurphy]

Add a client support package. This will be used in Rekor's integration tests and can be imported by Go-based Sigstore clients.

Depends on #119

TODO:

• verify inclusion proof from Add response
• add ReadCheckpoint
• add ReadTile
• add ReadEntryBundle
• remove verifyTLE and replace with verification functions from Create NoteVerifier, verification library functions #114
• add unit tests

Summary

Release Note

Documentation

[codecov]

Codecov Report

Attention: Patch coverage is 61.53846% with 90 lines in your changes missing coverage. Please review.

Project coverage is 26.25%. Comparing base (82230be) to head (875a7c4).

Files with missing lines	Patch %	Lines
pkg/note/note.go	22.72%	32 Missing and 2 partials ⚠️
pkg/client/write.go	75.47%	18 Missing and 8 partials ⚠️
pkg/client/read.go	52.63%	16 Missing and 2 partials ⚠️
pkg/client/common.go	68.42%	8 Missing and 4 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #113      +/-   ##
==========================================
+ Coverage   21.61%   26.25%   +4.64%     
==========================================
  Files          27       31       +4     
  Lines        1712     1935     +223     
==========================================
+ Hits          370      508     +138     
- Misses       1308     1378      +70     
- Partials       34       49      +15     

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[jku]

Suggested change

	func WithUserAent(agent string) Option {
	func WithUserAgent(agent string) Option {

[cmurphy]

Will rebase on #114 once merged and replace verifyTLE with verify.VerifyLogEntry.

[jku]

Will rebase on #114 once merged and replace verifyTLE with verify.VerifyLogEntry.

That is #119 now. I might not have time to get the tests done for that today: if you are in a hurry with this one feel free to use that branch here or merge it, just file an issue so I remember to write those tests...