Add missing Export-Package to mcp-json-jackson2 and mcp-json-jackson3

The bnd configs for mcp-json-jackson2 and mcp-json-jackson3 are missing
Export-Package, unlike mcp-core which correctly exports its packages.
Without Export-Package, all packages are sealed as bundle-private,
causing 'Access restriction' errors for consumers that use
Require-Bundle (e.g. Eclipse PDE / Tycho projects).

This was introduced in modelcontextprotocol#779 which added OSGi Declarative Services
support for modelcontextprotocol#562. The DS service registration works without exports
(SCR instantiates classes internally), but direct instantiation
such as 'new JacksonMcpJsonMapperSupplier()' from another bundle
requires the packages to be exported.

Add the same Export-Package directive used in mcp-core.

Author: joaodinissf

mcp-json-jackson2/pom.xml

@@ -40,6 +40,7 @@
 								Import-Package:         io.modelcontextprotocol.json,io.modelcontextprotocol.json.schema, \
 								                        *;
 								Service-Component: 		OSGI-INF/io.modelcontextprotocol.json.jackson2.JacksonMcpJsonMapperSupplier.xml,OSGI-INF/io.modelcontextprotocol.json.schema.jackson2.JacksonJsonSchemaValidatorSupplier.xml
+								Export-Package:         io.modelcontextprotocol.*;version="${project.version}";-noimport:=true
 								-noimportjava:          true;
 								-nouses:                true;
 								-removeheaders:         Private-Package

mcp-json-jackson3/pom.xml

@@ -40,6 +40,7 @@
 								Import-Package:         io.modelcontextprotocol.json,io.modelcontextprotocol.json.schema, \
 								                        *;
 								Service-Component: 		OSGI-INF/io.modelcontextprotocol.json.jackson3.JacksonMcpJsonMapperSupplier.xml,OSGI-INF/io.modelcontextprotocol.json.schema.jackson3.JacksonJsonSchemaValidatorSupplier.xml
+								Export-Package:         io.modelcontextprotocol.*;version="${project.version}";-noimport:=true
 								-noimportjava:          true;
 								-nouses:                true;
 								-removeheaders:         Private-Package