Proto commits in googleapis/gax-php

These 16 commits are when the Protocol Buffers files have changed:

Commit:4853405
Author:Brent Shaffer
Committer:Brent Shaffer

chore: prepare GAX for monorepo (https://github.com/googleapis/gax-php/issues/663)

Commit:5e6a12d
Author:Brent Shaffer
Committer:Brent Shaffer

fix: regenerate-test-protos script for directory refactor (https://github.com/googleapis/gax-php/issues/308)

Commit:a5c4cb7
Author:Brent Shaffer
Committer:Brent Shaffer

feat: support mapped fields in paged list response (https://github.com/googleapis/gax-php/issues/306)

The documentation is generated from this commit.

Commit:7a35d6e
Author:David Supplee
Committer:Brent Shaffer

New serialization approach for the RequestBuilder (https://github.com/googleapis/gax-php/issues/226) * Utilize serializeToJsonString over accessing protected/private properties * ignore metadata and src/Testing in code coverage

Commit:fc72aaf
Author:michaelbausor
Committer:Brent Shaffer

Remove common protos (https://github.com/googleapis/gax-php/issues/220) * Remove common protos * Remove ApiCore directory * Increase minimum protobuf version

Commit:ba43224
Author:michaelbausor
Committer:Brent Shaffer

Response metadata support (https://github.com/googleapis/gax-php/issues/175) * Support response metadata * Restructure paging and operations to use metadata

Commit:260a294
Author:Brent Shaffer
Committer:Brent Shaffer

fixes getQuerystringValue for special JSON cases (https://github.com/googleapis/gax-php/issues/156)

Commit:51719ad
Author:Brent Shaffer
Committer:Brent Shaffer

Add support for JSON Transport (https://github.com/googleapis/gax-php/issues/118) - Adds support for HTTP1.1 JSON transport - Large refactoring of ApiCore classes

Commit:2e53981
Author:Brent Shaffer
Committer:GitHub

chore: prepare GAX for monorepo (#663)

Commit:134366f
Author:Brent Shaffer
Committer:GitHub

feat: support mapped fields in paged list response (#306)

The documentation is generated from this commit.

Commit:94e2f3f
Author:Brent Shaffer
Committer:GitHub

fix: regenerate-test-protos script for directory refactor (#308)

Commit:816a2c1
Author:David Supplee
Committer:GitHub

New serialization approach for the RequestBuilder (#226) * Utilize serializeToJsonString over accessing protected/private properties * ignore metadata and src/Testing in code coverage

Commit:a69d51e
Author:michaelbausor
Committer:GitHub

Remove common protos (#220) * Remove common protos * Remove ApiCore directory * Increase minimum protobuf version

Commit:b3028ec
Author:michaelbausor
Committer:GitHub

Response metadata support (#175) * Support response metadata * Restructure paging and operations to use metadata

Commit:070d0a5
Author:Brent Shaffer
Committer:GitHub

fixes getQuerystringValue for special JSON cases (#156)

Commit:d27037b
Author:Brent Shaffer
Committer:michaelbausor

Add support for JSON Transport (#118) - Adds support for HTTP1.1 JSON transport - Large refactoring of ApiCore classes