datadog_trace 1.9.0

## All products
### Added
- Update config telemetry to support stable config #3198

## Tracer
### Added
- Support DD_DOGSTATSD_HOST configuration #3167
- Add referrer hostname as span tag #3196

### Changed
- Capture key before first colon in DD_TAGS #3179

### Fixed
- Check server first before accessing in ddtrace_ip_extraction_find #3216
- Fix assumptions around interned strings on PHP 7.3 #3224
- Fix initial double remote config reading #3225, #3238
- Fix dropped trace payloads for the sidecar Datadog/libdatadog#1047
- Fix Windows VirtualProtect call #3229

### Internal
- Store debug symbols in the SSI archive #3217

## Profiling
### Added
- Configurable allocation sampling distance #3227

### Changed
- Accept auto as valid value for DD_PROFILING_ENABLED #3166

### Fixed
- Fix empty internal metadata #3228
- Follow PHP globals model in allocation profiler #3175

### Internal changes
- Bump libdatadog to version 18 #3229

## Application Security Management
### Added
- AppSec support for Frankenphp #3165
- Detection/blocking of SQL injections through libddwaf #3186
- Add RASP_SQLI remote config capability #3203

### Fixed
- Make Appsec blocking compatible with Laravel error handler #3110