SC-2244: caches name/symbol in the registry

[godsflaw]

• adds caches for name and symbol
• gives auth the ability to change those

[godsflaw]

Running 24 tests for src/IlkRegistry.t.sol:IlkRegistryTest
[PASS] testListPartial() (gas: 1504152)
[PASS] testFailFileString() (gas: 244024)
[PASS] testJoin() (gas: 497203)
[PASS] testRemoveCaged() (gas: 1135275)
[PASS] testIlkData() (gas: 501253)
[PASS] testFileUint256() (gas: 255658)
[PASS] testWards() (gas: 7803)
[PASS] testIlks() (gas: 1237798)
[PASS] testFailFileUint256() (gas: 247112)
[PASS] testPos() (gas: 497165)
[PASS] testFailFileAddress() (gas: 247205)
[PASS] testSymbol() (gas: 250452)
[PASS] testFlip() (gas: 497159)
[PASS] testFailRemoveLive() (gas: 499803)
[PASS] testInfo() (gas: 765571)
[PASS] testFileString() (gas: 282306)
[PASS] testIlksPos() (gas: 492924)
[PASS] testDec() (gas: 745431)
[PASS] testAddIlk() (gas: 491070)
[PASS] testAuthRemoveLive() (gas: 768497)
[PASS] testName() (gas: 250430)
[PASS] testGem() (gas: 497247)
[PASS] testPip() (gas: 497267)
[PASS] testFileAddress() (gas: 285251)

[lucas-manuel]

LGTM