Blocks: branded filaments, naming/loading fixes, RF50 bed type and other fixes. (#15804)

# Description

<!--
> Please provide a summary of the changes made in this PR. Include
details such as:
  > * What issue does this PR address or fix?
  > * What new features or enhancements does this PR introduce?
> * Are there any breaking changes or dependencies that need to be
considered?
-->

This PR fixes some problems with the current profiles for Blocks
printers

- **Fix**: start gcode for the Blocks 0.6mm RF50 printer where the start
gcode command had no newline separation on two commands so they were
concatenated and would make printing fail.
- **Added**: multi material plates selection for the RF50 printers,
right now only textured PEI and smooth high temp plates are available,
but in the future more to come.
- **Naming consistancy** for Blocks Pro S100 processes and filaments,
target labels used bare `@Blocks` while RD50 and RF50 used
`@Blocks_RD50` and `@Blocks_RF50`. Renamed Pro S100 to
`@Blocks_Pro_S100` to match the structure.
- **Filament restructure**: replaced Blocks tuned-generic filaments
(e.g. `Generic PLA @Blocks`) with real Blocks-branded filaments. One for
each printer model. Every material keeps the same coverage we already
had.
- **Fix**: `sparse_infill_pattern` was misspelled `sparse_infill_patter`
on 13 `@Blocks_RF50` process presets. Harmless due to inheritances but
fixed non the less.
- **Fix**: `Blocks RD50 V2 0.4 nozzle.json` was missing
`printer_variant`.
- **Normalize** all Blocks profiles to standard formatting (tab
indentation, key order) and bumped `Blocks.json` version.
- **RF50 retraction length** increased on all RF50 machines.


## Tests

- [x] `orca_profile_tool.py check --vendor Blocks` - clean
- [x] `orca_profile_tool.py check` - clean
- [x] `normalize` / `generate-id` / `update-index --dry-run` — fully
settled, no pending changes
- [x] `check_profile.sh --vendor Blocks` → `profile_tool` check — passes
- [ ] `validate_system` / `validate_slice` /
`validate_filament_subtypes` / `validate_custom` —
could not run locally (dev host's glibc 2.36 is older than the nightly
validator binary's
      required 2.38); needs CI or a compatible host
- [x] In-app confirmation that the Blocks bundle loads
 
<!--
> A guide for users on how to download the artifacts from this PR.
-->

[How to Download Pull Requests Artifacts for
Testing](https://www.orcaslicer.com/wiki/how_to_download_pr_artifacts)

resources/profiles/Blocks/machine/BLOCKS Pro S100 0.8 nozzle.json

@@ -6,7 +6,7 @@
 	"setting_id": "I6PdeCS7SbvIlkZf",
 	"instantiation": "true",
 	"printer_model": "BLOCKS Pro S100",
-	"default_print_profile": "0.40mm Standard 0.8 nozzle @Blocks",
+	"default_print_profile": "0.40mm Standard 0.8 nozzle @Blocks_Pro_S100",
 	"max_layer_height": [
 		"0.56"
 	],
@@ -26,5 +26,8 @@
 	"upward_compatible_machine": [
 		"BLOCKS Pro S100"
 	],
-	"printer_variant": "0.8"
+	"printer_variant": "0.8",
+	"default_filament_profile": [
+		"Blocks PLA @Blocks_Pro_S100"
+	]
 }