Optimize the dependencies

**Describe the issue:**
With the current dependencies, the web apps being built using the java-saml-sdk tends to grow >50MB in size.
To avert this, we need to optimize the dependencies added in the https://github.com/asgardeo/asgardeo-java-saml-sdk/blob/master/pom.xml

Start by reviewing pom.xml and measuring how the current dependencies contribute to the web-app size. Identify dependencies that can be reduced or removed while preserving the SDK, then verify that the resulting application artifact is smaller than the current build and still works.

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