Update documentation for runtime events and metadata extraction

[phoyo008]

Ten core interceptor event files were previously stubs — they listed event names but provided no information about what data each event carries, when it fires, or how to write a listener. This PR fully documents all of them with typed data payload tables and BoxLang listener examples.

All core interceptor event files follow a consistent three-part structure per event:

1. Event Description

Each event opens with a plain-language explanation of when it fires and what it is useful for. Example:

Fired after the runtime has fully started up. Use this to run startup logic that depends on the runtime being ready.

---

2. Files Updated

File	Events Documented
runtime-events.md	onRuntimeStart, onRuntimeShutdown, onRuntimeConfigurationLoad, onRuntimeBoxContextStartup, onServerScopeCreation, onConfigurationLoad, onConfigurationOverrideLoad, onParse, onMissingMapping
application-events.md	onApplicationStart, onApplicationEnd, onSessionStart, onSessionEnd, onRequestStart, onRequestEnd, onAbort, onError, onMissingTemplate
request-context-events.md	onRequestContextStart, onRequestContextEnd, onRequestContextClose
template-invocations.md	preTemplateInvoke, postTemplateInvoke
function-invocations.md	preFunctionInvoke, postFunctionInvoke
life-cycle-events.md	onBIFInvoke, onComponentInvoke, onComponentCreate, onComponentDestroy
object-marshalling-events.md	beforeObjectMarshallSerialize, afterObjectMarshallSerialize, beforeObjectMarshallDeserialize, afterObjectMarshallDeserialize
cache-object-store-events.md	onCacheObjectStoreSet, onCacheObjectStoreGet, onCacheObjectStoreDelete, onCacheObjectStoreClear
logging-events.md	logMessage
dump-events.md	onDump

3. What Each File Now Contains

Every event section includes:

• Description — when the event fires and why it's useful
• Data Structure table — every key the event passes, its type, and what it represents
• Example — a working BoxLang class listener showing how to handle the event

[lmajano]

Few comments and we can merge

[bdw429s]

@phoyo008 You have this many times in the examples

class myListener{

but this is not proper syntax for BoxLang as we don't declare the class name there. Make these just be

class {