Make "process" a required input and configure pyconf functions globally once with user input

Closes #59 (closed) and closes #74 (closed).

• Make process a required input.
• Make "options.process" as the default input to algorithms (e.g. truth matching).
• Make process a required input to truth-matching algorithm (related to issue: #62 (closed)) and also set correct root-in-tes for Turbo process.

To be tested with: LHCb!3806 (merged), Moore!1812 (merged) and Analysis!914 (merged)

Phys/DaVinci/python/DaVinci/LbExec.py

@@ -11,6 +11,7 @@
 from contextlib import contextmanager
 from typing import Optional
 from GaudiConf.LbExec import Options as DefaultOptions, ProcessTypes
+from pydantic import root_validator
 from PyConf.reading import (upfront_decoder, reconstruction, get_tes_root,
                             get_odin, get_hlt_reports, get_mc_track_info)
 
@@ -48,13 +49,30 @@ class Options(DefaultOptions):
     metainfo_additional_tags: Optional[list]
     annsvc_config: Optional[str]
     process: ProcessTypes
-    stream: str = "default"
+    stream: Optional[str] = 'default'
     lumi: bool = False
     evt_pre_filters: Optional[dict[str, str]] = None
     enable_unpack: bool = True
     write_fsr: bool = True
     merge_genfsr: bool = False
 
+    @root_validator(pre=False)
+    def _stream_default(cls, values):
+      """
+      This is a validator that sets the default "stream" value based on "process"
+
+      Args:
+        values (dict): User-specified attributes of the Options object.
+
+      Returns:
+        dict: Modified attributes of the Options object
+      """
+      process = values.get("process")
+      if process == ProcessTypes.Hlt2:
+        values['stream'] = ''
+
+      return values
+
     @contextmanager
     def apply_binds(self):
         """