Update applyAsMentor method with new fields

[Madhawa97]

Purpose

The purpose of this PR is to fix #228

Goals

Mentors should be able to update all fields using applyAsMentor endpoint

Approach

Update the src/main/java/org/sefglobal/scholarx/service/ProgramService.java:applyAsMentor method to set the following fields.

1. category
2. expertise
3. institution
4. position
5. bio
6. slots

Screenshots

Checklist

• This PR doesn't commit any keys, passwords, tokens, usernames, or other secrets.
• I have read and understood the development best practices guidelines ( http://bit.ly/sef-best-practices )
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation

Related PRs

Test environment

Learning

[Piumal1999]

Good job! Thank you @Madhawa97

[Madhawa97]

You're welcome @Piumal1999