marker: tighten marker name max length from 128 to 32

128 characters was far beyond any realistic marker label (icmp, arp, tcp-syn)
and would have collided with the pcap filename budget once a tag prefix is
added later. Cap the user-facing name at 32 in both MarkerCreate and
MarkerDefinitionCreate; the compute-side name guard now also rejects names
longer than 48, which covers the `global-{def_name}` inherited form (≤ 39).

gns3server/schemas/controller/links.py

@@ -152,7 +152,7 @@ class MarkerCreate(BaseModel):
     name: Optional[str] = Field(
         None,
         pattern=r"^[A-Za-z0-9][A-Za-z0-9_.-]*$",
-        max_length=128,
+        max_length=32,
         description='Unique marker name on the link. Auto-generated when absent.',
     )
     bpf: str
@@ -236,7 +236,7 @@ class MarkerDefinitionCreate(BaseModel):
     name: Optional[str] = Field(
         None,
         pattern=r"^[A-Za-z0-9][A-Za-z0-9_.-]*$",
-        max_length=128,
+        max_length=32,
         description="Unique definition name. Auto-generated when absent.",
     )
     bpf: str