jaegerremote: Add WithSamplingStrategyFetcher option

[morus12]

• Fixed an issue where the fetcher would panic if the default transport is not of type *http.Transport due to the cast:
  
  customTransport := http.DefaultTransport.(*http.Transport).Clone()
  
  To address this, we've now set the http.Client.Timeout rather than customTransport.ResponseHeaderTimeout to prevent panic.

• This PR exposes SamplingStrategyFetcher and WithSamplingStrategyFetcher, enabling the definition of a custom fetcher that utilizes a custom HTTP client with a transport other than *http.Transport. We have integrated httpmock, which clashes with the default http.Client. To address this, we employ custom HTTP clients in our fetcher implementation.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: morus12 / name: Grzegorz Wyszyński (773069e, 3a9b806, b07e695, 65af938, 21e210a, 0312cc8, 9211383, e0ec2d9, b16140a, 7e25759, 27a19f0, df5262b, 3296dca, 6862657, a00573d, 51c2c31)
• ✅ login: dmathieu / name: Damien Mathieu (3296dca)

[dmathieu]

Please add a unit test.

[MrAlias]

Please sign the CLA so these changes can be considered.

[codecov]

Codecov Report

Merging #4045 (51c2c31) into main (9d4eb7e) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #4045   +/-   ##
=====================================
  Coverage   82.2%   82.2%           
=====================================
  Files        144     144           
  Lines      10005   10002    -3     
=====================================
  Hits        8226    8226           
+ Misses      1638    1636    -2     
+ Partials     141     140    -1     

Files	Coverage Δ
samplers/jaegerremote/sampler_remote.go	89.4% <100.0%> (-0.3%)	⬇️
samplers/jaegerremote/sampler_remote_options.go	100.0% <100.0%> (ø)

... and 1 file with indirect coverage changes

It looks like Jaeger sampling is deprecated

[pellared]

PS. Only "Client Sampling" is deprecated https://www.jaegertracing.io/docs/1.47/sampling/

[pellared]

This branch is out-of-date with the base branch

@morus12 Can you please update the branch?

comments need adressing

[pellared]

Few things needs to be addressed.

[pellared]

@morus12 Do you plan to update the PR and address the comments?

[morus12]

1. I added comments.
2. Set the defaultRemoteSamplingTimeout only when http.DefaultClient.Transport is *http.Transport.
3. Test if defaultRemoteSamplingTimeout is set when conditions are met.
4. Test if there is no panic with custom http.DefaultClient.Transport.

Let me know if you need any other changes.

PR has significant changes.

[pellared]

Waiting for codeowner (@yurishkuro) review.

[yurishkuro]

Lgtm, although I don't follow the need to clone the transport.

[pellared]

@morus12 Please address #4045 (comment) and update the branch and I will merge the PR 🎉

[pellared]

@morus12 Thank you for your contribution and have a nice weekend 😉

[morus12]

I appreciate your help!
It was an exciting challenge, maybe I'll pick up another issue ;)