about raw data api

For our scenario, we'll add a static/deploy.j2 to helm chart to render the helm charts information

So we need to get this file through the api,

However, the current api does not support it, as follows:

```go

chartManipulationRoutes := []*cm_router.Route{
{Method: "GET", Path: "/api/:repo/charts", Handler: s.getAllChartsRequestHandler, Action: cm_auth.PullAction},
{Method: "HEAD", Path: "/api/:repo/charts/:name", Handler: s.headChartRequestHandler, Action: cm_auth.PullAction},
{Method: "GET", Path: "/api/:repo/charts/:name", Handler: s.getChartRequestHandler, Action: cm_auth.PullAction},
{Method: "HEAD", Path: "/api/:repo/charts/:name/:version", Handler: s.headChartVersionRequestHandler, Action: cm_auth.PullAction},
{Method: "GET", Path: "/api/:repo/charts/:name/:version", Handler: s.getChartVersionRequestHandler, Action: cm_auth.PullAction},
{Method: "GET", Path: "/api/:repo/charts/:name/:version/templates", Handler: s.getStorageObjectTemplateRequestHandler, Action: cm_auth.PullAction},
{Method: "GET", Path: "/api/:repo/charts/:name/:version/values", Handler: s.getStorageObjectValuesRequestHandler, Action: cm_auth.PullAction},
{Method: "POST", Path: "/api/:repo/charts", Handler: s.postRequestHandler, Action: cm_auth.PushAction},
{Method: "POST", Path: "/api/:repo/prov", Handler: s.postProvenanceFileRequestHandler, Action: cm_auth.PushAction},
}

```
In the helm charts definition, the raw field can be as follows:
```go
type Chart struct {
// Raw contains the raw contents of the files originally contained in the chart archive.
//
// This should not be used except in special cases like `helm show values`,
// where we want to display the raw values, comments and all.
Raw []*File `json:"-"`
// Metadata is the contents of the Chartfile.
Metadata *Metadata `json:"metadata"`
// Lock is the contents of Chart.lock.
Lock *Lock `json:"lock"`
// Templates for this chart.
Templates []*File `json:"templates"`
// Values are default config for this chart.
Values map[string]interface{} `json:"values"`
// Schema is an optional JSON schema for imposing structure on Values
Schema []byte `json:"schema"`
// Files are miscellaneous files in a chart archive,
// e.g. README, LICENSE, etc.
Files []*File `json:"files"`

parent *Chart
dependencies []*Chart
}
```
Can we provide the relevant api?
for example:
```go
{Method: "GET", Path: "/api/:repo/charts/:name/:version/raw", Handler: s.getStorageObjectRawRequestHandler, Action: cm_auth.PullAction},

```

I can contribute this pr