Convert ChainNetwork type to string.

[jnaviask]

Link to Issue

Affects but does not close #8762

Description of Changes

• Patch for Migrated app.config.chain.getById() calls to newer trpc.community.getCommunity() + cleanup/state-refactor of related components #8779 to eliminate ChainNetwork field.

"How We Fixed It"

Converted type to string rather than using an enum type, as arbitrary values are possible and not necessary to account for due to lack of specific logic in most cases.

Test Plan

• Ensure no type errors result from unknown enum values (the current ChainNetwork enum should capture all explicit uses).
• Ensure regen loads as expected and no TRPC errors in server console.
• Ensure communities page functions as expected.

[mzparacha]

Thanks! Works great on /regen and /communities pages.

I noticed another zod issue with substrate_spec field

err: {
      "type": "ZodError",
      "message": "[\n  {\n    \"code\": \"invalid_type\",\n    \"expected\": \"string\",\n    \"received\": \"object\",\n    \"path\": [\n      \"substrate_spec\"\n    ],\n    \"message\": \"Expected string, received object\"\n  }\n]",
      "stack":
          ZodError: [
            {
              "code": "invalid_type",
              "expected": "string",
              "received": "object",
              "path": [
                "substrate_spec"
              ],
              "message": "Expected string, received object"
            }
          ]

but this is unrelated and can be fixed in 8779 (if you prefer).

[jnaviask]

@mzparacha we can eliminate the substrate spec field entirely. I will make a separate PR for this against master.