Update analyze's error message to provide better clarity

Example session:

```sh
$ ramble workspace analyze --where '{experiment_index} == 1'
==> Streaming details to log:
==>   /usr/local/google/home/linsword/hpc-dev/ramble/var/ramble/workspaces/hostname-test/logs/analyze.2024-09-11_13.12.38.out
==>   Analyzing 1 out of 12 experiments:
==> Error: No analyzeable experiment detected. All selected ones are either templates or the base of repeated experiments.

$ ramble workspace analyze --where '{experiment_index} == 13'
==> Streaming details to log:
==>   /usr/local/google/home/linsword/hpc-dev/ramble/var/ramble/workspaces/hostname-test/logs/analyze.2024-09-11_13.12.44.out
==>   Analyzing 0 out of 12 experiments:
==> Error: No experiment left for analysis after filtering.
```

lib/ramble/ramble/pipeline.py

@@ -248,12 +248,26 @@ def _prepare(self):
         # - At least one expeirment is set up
         # - `--dry-run` is enabled
         found_valid_experiment = False
-        for exp, app_inst, _ in self._experiment_set.filtered_experiments(self.filters):
+        # Record how many non-analyzable experiments are encountered
+        no_analyze_cnt = 0
+        for _, app_inst, _ in self._experiment_set.filtered_experiments(self.filters):
             if not (app_inst.is_template or app_inst.repeats.is_repeat_base):
                 if app_inst.get_status() != ramble.application.experiment_status.UNKNOWN.name:
                     found_valid_experiment = True
-
-        if not found_valid_experiment and self._experiment_set.num_experiments():
+            else:
+                no_analyze_cnt += 1
+
+        num_total_exps = self._experiment_set.num_experiments()
+        num_filtered_exps = self._experiment_set.num_filtered_experiments(self.filters)
+        if not found_valid_experiment and num_total_exps:
+            if not num_filtered_exps:
+                logger.die("No experiment left for analysis after filtering.")
+            if num_filtered_exps == no_analyze_cnt:
+                logger.die(
+                    "No analyzeable experiment detected."
+                    " All selected ones are either templates or the base of"
+                    " repeated experiments."
+                )
             logger.die(
                 "No analyzeable experiment detected."
                 " Make sure your workspace is setup with\n"