Add health endpoint to dynamic text gen server

[santhnm2]

What does this PR do ?

Adds a health endpoint to the dynamic text generation server.

Contribution process

flowchart LR
    A[Pre-checks] --> B[PR Tests]
    subgraph Code Review/Approval
        C1[Expert Review] --> C2[Final Review]
    end
    B --> C1
    C2 --> D[Merge]

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Pre-checks

• I want this PR in a versioned release and have added the appropriate Milestone (e.g., Core 0.8)
• I have added relevant unit tests
• I have added relevant functional tests
• I have added proper typing to my code Typing guidelines
• I have added relevant documentation
• I have run the autoformatter.sh on my PR

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[santhnm2]

/ok to test 874eb25

[santhnm2]

/ok to test 6f87c0f

[santhnm2]

/ok to test 2f02d84

[santhnm2]

/ok to test 920034d

[santhnm2]

/ok to test a4fc2df