Export GetCodecMap for payload lookups (#248)

Rename buildCodecMap to GetCodecMap so callers can
build the codec map once and reuse it for multiple
payload type lookups.

This is needed by pion/webrtc's
codecsFromMediaDescription (sdp.go:1101), which
calls GetCodecForPayloadType in a loop
(sdp.go:1112), rebuilding the full codec map on
every iteration. With GetCodecMap exported, webrtc
can build the map once and do direct lookups.

Update CI configs to v0.11.39

Update lint scripts and CI configs.

Add ice renomination option

Update CI configs to v0.11.26

Update lint scripts and CI configs.

Add lenient parsing for incomplete origin lines

Support non-compliant SDP origin lines missing address type
or unicast address fields, commonly found in security cameras.

- Add fallback to default values when fields are missing
- Maintain RFC4566 compliance for complete origin lines
- Add comprehensive test coverage for edge cases

Fixes compatibility with Uniview and other camera manufacturers
that generate non-compliant SDP.

Handle missing AddressType/UnicastAddress fields in SDP from
IP cameras by setting RFC-compliant defaults (IP4/0.0.0.0, IP6/::).
Maintains strict error handling for unexpected failures.

Fixes compatibility with Uniview and similar cameras.

- Extract handleAddressType/handleUnicastAddress helpers

Added attribute cryptex

This attribute is used to negotiate encryption of RTP Header Extensions
and Contributing Sources as specified in RFC 9335.

Revert "Error on conflicting codec values"

This reverts commit c7c57e2.

Error on conflicting codec values when parsing

Resolves #198

Upgrade golangci-lint, more linters (#194)