feat: support bitnamic etcd chart and add charts cache

[zyy17]

What's changed

1. Support bitnami etcd chart that stores in OCI registry;
2. Support helm charts cache;
3. Refactor helm Render and rename to Manager, and simplify the interface(the user only need to call one API LoadAndRenderChart());

Related issues

• Add charts cache #133
• Support bitnami etcd chart #88

[codecov-commenter]

Codecov Report

Merging #135 (1d2da17) into develop (294be69) will increase coverage by 12.44%.
Report is 4 commits behind head on develop.
The diff coverage is 53.67%.

@@             Coverage Diff              @@
##           develop     #135       +/-   ##
============================================
+ Coverage    21.94%   34.38%   +12.44%     
============================================
  Files            8        8               
  Lines          948     1079      +131     
============================================
+ Hits           208      371      +163     
+ Misses         683      621       -62     
- Partials        57       87       +30     

Files Changed	Coverage Δ
pkg/cmd/gtctl/cluster/create/create.go	0.00% <0.00%> (ø)
pkg/helm/helm.go	52.54% <54.47%> (+19.21%)	⬆️

... and 1 file with indirect coverage changes

[shawnh2]

in e2e, it seems has trouble creating the cluster

[zyy17]

@shawnh2 The PDB resources(generated by bitnami etcd chart) that use policy/v1beta1 are removed in K8s v1.25+. I use the fixed kind node image v1.24.15 to fix it.

[shawnh2]

lgtm