Resolve Issues V3.1

[BirgitBoss]

Specification updated conformant to the accepted changes to V3.1

Major Changes:

• New value "Role" to enumeration AssetKind closes #294
• PathType: support complete URI scheme for files RFC3986/RFC3987 closes #299
• data type Identifier: change length from 2000 to 2024 characters closes #306
• Referable/idShort and Constraint AASd-002: now also allows hyphens to be included in name closes #295
• Entity/entityType and Constraint AASd-014: now optional closes #287

Minor Changes:

• editorial changes

Bugfixes:

• (Editorial) MultiLanguageNameType inconsistent description, maxLength=128 (schemata were correct) part of #313
• (Editorial) HasKind/kind explanataroy text: use template, not type part of #313
• (Editorial) DataTypeDefXsd links now correctly to xmlschema11-2, not to xsd V1.1 closes #312
• (Editorial) make mbeddedDataSpecification/dataSpecification mandatory (as implemented in schemata) closes #296
• (Editorial) Text was fixed w.r.t. Referables and exception with SubmodelElementList
• remove <<DataType>> Stereotype from UML Annex since not used any longer (part of #313)

closes #313