feat(proxy-wasm) allow cancelling background ticks

[thibaultcha]

Passing 0 to set_tick_period signifies "cancel the tick".

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 90.61814%. Comparing base (b8aae2c) to head (d00a35a). Report is 2 commits behind head on main.

Files	Patch %	Lines
src/common/proxy_wasm/ngx_proxy_wasm_host.c	88.88889%	1 Missing :warning:

Additional details and impacted files

[](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) ```diff @@ Coverage Diff @@ ## main #579 +/- ## =================================================== + Coverage 90.60126% 90.61814% +0.01688% =================================================== Files 49 49 Lines 10927 10936 +9 =================================================== + Hits 9900 9910 +10 + Misses 1027 1026 -1 ``` | [Files](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) | Coverage Δ | | |---|---|---| | [src/common/proxy\_wasm/ngx\_proxy\_wasm\_util.c](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579?src=pr&el=tree&filepath=src%2Fcommon%2Fproxy_wasm%2Fngx_proxy_wasm_util.c&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong#diff-c3JjL2NvbW1vbi9wcm94eV93YXNtL25neF9wcm94eV93YXNtX3V0aWwuYw==) | `94.20849% <100.00000%> (+0.06786%)` | :arrow_up: | | [src/common/proxy\_wasm/ngx\_proxy\_wasm\_host.c](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579?src=pr&el=tree&filepath=src%2Fcommon%2Fproxy_wasm%2Fngx_proxy_wasm_host.c&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong#diff-c3JjL2NvbW1vbi9wcm94eV93YXNtL25neF9wcm94eV93YXNtX2hvc3QuYw==) | `93.82857% <88.88889%> (+0.00705%)` | :arrow_up: | ... and [3 files with indirect coverage changes](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) | [Flag](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) | Coverage Δ | | |---|---|---| | [unit](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) | `90.33706% <91.66667%> (+0.01952%)` | :arrow_up: | | [valgrind](https://app.codecov.io/gh/Kong/ngx_wasm_module/pull/579/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong) | `82.13065% <91.66667%> (+0.01257%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Kong#carryforward-flags-in-the-pull-request-comment) to find out more.