- Introduced idle connection timeout for HTTP client transport
- Implemented custom timeout for HTTP client when `RelayTimeout` is 0
- Set ImpatientHTTPClient timeout to 5 seconds
- Added new config variable `IdleTimeout` with default value of 30 seconds
- Utilized shared transport object for all HTTP clients in relay/util package
- Modify `PostConsumeQuota` function in `common.go` to check if `totalQuota` is less than 0 and add error logging
- Update log content in `RecordConsumeLog` function of `common.go` to include model ratio and group ratio
- Change the method of calculating user used quota and request count in `UpdateUserUsedQuotaAndRequestCount` function of `common.go`
- Implement calculation of `completionRatio` and update `quota` calculation based on `completionRatio` in `postConsumeQuota` function of `helper.go`
- Implement error handling for `model.PostConsumeTokenQuota` and `model.CacheUpdateUserQuota` in `helper.go`
- Update `UserUsedQuota` and `ChannelUsedQuota` with new `quota` value in `helper.go`
