expose condition api

[XiaofeiCao]

Description

fix #25815
This PR exposes condition() api on RoleAssignment.
Test is done locally.

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[weidongxu-microsoft]

Could you show us a sample string of this condition in real case?

[XiaofeiCao]

The condition string looks like this:

(
 (
  !(ActionMatches{'Microsoft.Storage/storageAccounts/blobServices/containers/blobs/read'} AND SubOperationMatches{'Blob.Read.WithTagConditions'})
 )
 OR 
 (
  @Resource[Microsoft.Storage/storageAccounts/blobServices/containers:name] StringEquals 'test'
 )
)

Corresponding portal assign parameters: